GUI wizard installer on TeXLive 2021 auto-defaulting to main installer in Linux

Question

I'm not sure why, but for some reason the -gui option is voiding with errors when installing TeXLive 2021 on Linux. Thus:

clive@clivux:~/Downloads/install-tl-20210925$ sudo ./install-tl -gui=wizard -select-repository 
[sudo] password for clive: 
Can't exec "wish": No such file or directory at ./install-tl line 134.
Can't exec "wish8.7": No such file or directory at ./install-tl line 134.
Can't exec "wish8.6": No such file or directory at ./install-tl line 134.
Can't exec "wish8.5": No such file or directory at ./install-tl line 134.
Can't exec "tclkit": No such file or directory at ./install-tl line 134.
UI plugin wizard not found,
Using text mode installer.
Please select a repository:

AFRICA
 [1]   Algeria       http://ctan.epst-tlemcen.dz/tex-archive

[...]

SOUTH AMERICA
[115]   Chile         https://ctan.dcc.uchile.cl
----
[0] default mirror   http://mirror.ctan.org
[q] quit
Your selection  [0]: 

I peeked inside the install-tl file to look at line 134, but I'm nervous about changing anything for fear of breaking the file (there should be no need to edit it, anyway, as there hasn't been a need before).

Using -gui, -gui=perltk and -gui=tci as alternative optional flags all produce the same result. I can, of course, use the text mode installer in bash, but I prefer to use the GUI wizard.

Needless to say, the current versions of p7zip, perltk and tci are already installed on my Linux PC system, of which see below:

clive@clivux:~$ inxi -Fxz
System:    Kernel: 5.11.0-36-generic x86_64 bits: 64 compiler: gcc v: 10.2.1 Desktop: KDE Plasma 5.21.4 
           Distro: Ubuntu 21.04 (Hirsute Hippo) 
Machine:   Type: Laptop System: HP product: HP 255 G6 Notebook PC v: Type1ProductConfigId serial: <filter> 
           Mobo: HP model: 8330 v: 27.33 serial: <filter> UEFI: Insyde v: F.31 date: 07/25/2018 
Battery:   ID-1: BAT1 charge: 29.7 Wh condition: 29.7/31.1 Wh (96%) model: Hewlett-Packard PABAS0241231 status: Full 
CPU:       Info: Dual Core model: AMD A6-9225 RADEON R4 5 COMPUTE CORES 2C+3G bits: 64 type: MCP arch: Excavator rev: 0 
           L2 cache: 1024 KiB 
           flags: avx avx2 lm nx pae sse sse2 sse3 sse4_1 sse4_2 sse4a ssse3 svm bogomips: 10381 
           Speed: 2056 MHz min/max: 1300/2600 MHz boost: enabled Core speeds (MHz): 1: 2056 2: 1297 
Graphics:  Device-1: Advanced Micro Devices [AMD/ATI] Stoney [Radeon R2/R3/R4/R5 Graphics] vendor: Hewlett-Packard 
           driver: amdgpu v: kernel bus ID: 00:01.0 
           Device-2: Quanta HP Webcam type: USB driver: uvcvideo bus ID: 2-1:2 
           Display: x11 server: X.Org 1.20.11 driver: loaded: amdgpu,ati unloaded: fbdev,modesetting,vesa 
           resolution: 1366x768~60Hz 
           OpenGL: renderer: AMD STONEY (DRM 3.40.0 5.11.0-36-generic LLVM 12.0.0) v: 4.5 Mesa 21.0.3 direct render: Yes 
Audio:     Device-1: Advanced Micro Devices [AMD/ATI] vendor: Hewlett-Packard driver: snd_hda_intel v: kernel bus ID: 00:01.1 
           Device-2: Advanced Micro Devices [AMD] Family 15h Audio vendor: Hewlett-Packard driver: snd_hda_intel v: kernel 
           bus ID: 00:09.2 
           Sound Server: ALSA v: k5.11.0-36-generic 
Network:   Device-1: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet vendor: Hewlett-Packard driver: r8169 v: kernel 
           port: 3000 bus ID: 02:00.0 
           IF: enp2s0 state: down mac: <filter> 
           Device-2: Intel Dual Band Wireless-AC 3168NGW [Stone Peak] driver: iwlwifi v: kernel port: 3000 bus ID: 03:00.0 
           IF: wlp3s0 state: up mac: <filter> 
Bluetooth: Device-1: Intel Wireless-AC 3168 Bluetooth type: USB driver: btusb v: 0.8 bus ID: 1-1.4:3 
           Report: ID: hci0 state: up running bt-v: 2.1 lmp-v: 4.2 address: <filter> 
Drives:    Local Storage: total: 931.51 GiB used: 43.85 GiB (4.7%) 
           ID-1: /dev/sda vendor: Seagate model: ST1000LM035-1RK172 size: 931.51 GiB temp: 41 C 
Partition: ID-1: / size: 913.74 GiB used: 43.17 GiB (4.7%) fs: ext4 dev: /dev/dm-1 mapped: vgkubuntu-root 
           ID-2: /boot size: 704.5 MiB used: 379.9 MiB (53.9%) fs: ext4 dev: /dev/sda2 
           ID-3: /boot/efi size: 511 MiB used: 5.2 MiB (1.0%) fs: vfat dev: /dev/sda1 
Swap:      ID-1: swap-1 type: partition size: 976 MiB used: 307.1 MiB (31.5%) dev: /dev/dm-2 mapped: vgkubuntu-swap_1 
Sensors:   System Temperatures: cpu: 30.0 C mobo: 20.0 C gpu: amdgpu temp: 29.0 C 
           Fan Speeds (RPM): N/A 
Info:      Processes: 215 Uptime: 7h 24m Memory: 3.72 GiB used: 2.21 GiB (59.5%) Init: systemd runlevel: 5 Compilers: 
           gcc: 10.3.0 Packages: 2534 Shell: Bash v: 5.1.4 inxi: 3.3.01 

Many thanks in anticipation of your help.