How can I take off "section x" from the frame of section page? (beamer)

Question

I am trying to make a presentation in beamer and there are parts where before starting a new section I would like their names to appear highlighted, for example like the title page (image bellow), but withou author name, date and institute.

I used it \frame{\sectionpage} for a frame of the section page. This is what I got.

But still appears "Section 1" and I want to take it of to only appear my section title, for exemple "Conceitos Introdutórios". Note: Every time I try to do a new section page it will appear "Section" followed by it's section number, it's not exclusive for the first one.

This is my code:

\documentclass{beamer}
        %\usepackage[latin1]{inputenc}
        %\usepackage[portuges]{babel}
        \usepackage{pstricks}
        \usepackage{graphicx}
        \usepackage{caption}
        \usepackage{subcaption}
        \usepackage{amsmath}
        \usepackage{tikz}
        \graphicspath{ {./images/} }
        \RequirePackage{ragged2e} \addtobeamertemplate{block
        begin}{}{\justifying} \justifying
        \usetheme{Madrid}
        \usefonttheme[onlysmall]{structurebold}
        \useinnertheme{circles}
        \usepackage{euler}
        \setbeamerfont{frametitle}{size=\Large}
%title
        \author[Miguel Godinho]{Miguel Godinho}
        
        
        \date[\today]{\small\today}
        \title[Relatividade Restrita]{\LARGE{Relatividade Restrita} \\ \large{Pensamento Relativístico}}
        
        \institute[Universidade do Minho]{Universidade do Minho}
        
        
        
        \begin{document}
%frame title
        \begin{frame}[plain]
        \titlepage
        \end{frame}
        
%section 
        \section{Conceitos Introdutórios}
        %frame section
        \frame{\sectionpage}
        \end{document}

So how can I take off "section "X""?

PS: I already did make this question but I changed so much and it was closed because it was not clear enough. I changed again and posting again (deleting the other one). Hope that's okay and hope it is more clear now.

Edit: I already tried to make a different default with a \setbeamertemplete :

    \setbeamertemplate{section page}
{
  \begin{centering}
    \begin{beamercolorbox}[center]{title}
      \usebeamerfont{title}\insertsection\par
    \end{beamercolorbox}
  \end{centering}
}

And the "section X" disappeared but it changed a lot of the box of the section title:

Answer 1

I found out the answer. If I use this \setbeamertemplate{section page}:

\setbeamertemplate{section page}{  \begingroup    \centering     \begin{beamercolorbox}[sep=12pt,center,colsep=-4bp,rounded=true,shadow=true]{section title}       \usebeamerfont{section title}\insertsection\par     \end{beamercolorbox}   \endgroup }

I got what I want: