Centering Abstract title and adding it to table of contents in overleaf

Question

I am trying to add the abstract to my document in LaTeX and I have two issues:

1. Abstract title not in center
2. Abstract not being added in the toc.

Is there any way to do both? There are a lot of solutions that do only one of the above but not both. Also, I wouldn't want the abstract to be a separate chapter.

I have tried using below in the main.tex

\begin{abstract}
    Here goes the body of the abstract
\end{abstract}

This keeps the abstract title itself to the left.

The second attempt I created a new file and called this in the main.tex:

\thispagestyle{plain}
\begin{center}
\phantomsection
\end{center}
\begin{abstract}
    Here goes the body of the abstract
\end{abstract}
\tableofcontents

This does add it to the table of contents but the Abstract title is again to the left. is there any way I could achieve centralizing the abstract title and adding it to the table of contents without making it a chapter? Any help would be appreciated.

Below is the entire class:

\documentclass[12pt,oneside, english, singlespacing,alternatives: onehalfspacing or doublespacing,consistentlayout,]{MastersDoctoralThesis}
\usepackage[utf8]{inputenc} 
\usepackage[T1]{fontenc} 
\usepackage{tikz}
\usepackage{float}
\usepackage[export]{adjustbox}
\usepackage{listings}
\usepackage{xcolor}
\usepackage{lipsum}
\AtBeginDocument{
\hypersetup{pdftitle=\ttitle} % Set the PDF's title to your title
\hypersetup{pdfauthor=\authorname} % Set the PDF's author to your name
\hypersetup{pdfkeywords=\keywordnames} % Set the PDF's keywords to your keywords
}
\begin{document}
\begin{abstract}
\addcontentsline{toc}{chapter}{Abstract}
    Body of the content
\end{abstract}
\end{document}