How to make the word "Abstract" appear separately above the abstract text itself?

Question

I am writing my first mathematical academic paper.

I am using document "article" class with "amsmaths" package. I want the word "Abstract" to actually appear centered in bold on a separate line, with one line extra spacing, above the paragraph containing the abstract itself. How can I do so? I am using \maketitle with \begin{abstract} and \end{abstract} and it works fine to produce the abstract text itself, but the word "abstract" doesn't show in the output pdf file in my current code.

My code:

\documentclass[10pt]{article}

\usepackage{graphicx}

\usepackage{authblk}

\usepackage{amsfonts}

\usepackage{mathtools, cuted}

\usepackage{lipsum, color}

\usepackage[margin=1.8cm]{geometry}

\usepackage{amsthm}

\author{Author}

\affil{Some university}

\affil{\textit {some email}}

\usepackage{appendix}

\renewcommand{\abstractname}{}

\addtolength{\baselineskip}{1.2}


\begin{document}

\title{Some title}

\maketitle

\

\begin{abstract}
Some text here
\end{abstract}

Answer 1

Avoid borrowing your buddy's preamble without knowing what every part of it does.

In this case the line

\renewcommand{\abstractname}{}

is the obvious culprit, because it says LaTeX you want no title above the abstract.

Here's a reorganized version of your preamble, with some error fixing.

\documentclass[10pt]{article}
\usepackage[margin=1.8cm]{geometry}

\usepackage{mathtools} % for math
\usepackage{amsfonts} % for \mathbb
\usepackage{amsthm} % for theorems

% general purpose
\usepackage{graphicx}
\usepackage{color}

% formatting
\usepackage{authblk}
\usepackage{cuted} % do I really need this?
\usepackage{appendix}

% misc packages
\usepackage{lipsum} % just for the example

% settings
\linespread{1.2} % increase distances between base lines
%\renewcommand{\abstractname}{} % no title above abstract

% personal commands
%\newcommand{\foo}{something} % just as a signpost

% metadata
\author{Author}
\affil{Some university \\ \textit {some email}}
\title{Some title}

\begin{document}

\maketitle

\begin{abstract}
\lipsum*[2]
\end{abstract}

\section{Introduction}

\lipsum

\end{document}