Edit:
I am able to successfully download python 3.7 on my Windows
As commented by @CrazyChucky and @Brian
3.7.9 is the latest 3.7 python with pre-build Windows installers
https://www.python.org/downloads/release/python-379/
3.7.17 is the latest version with security patches. It contains gzipped and XZ compresses files.
https://www.python.org/downloads/release/python-3717/

Python 3.7 help
Installation guide for Python 3.7 for Windows 11 - Stack Overflow
Installing Python 3.7 - Everything Else - Anaconda Forum
pip - How to install Python 3.7 in google colab? - Stack Overflow
Videos
Hi, so, I'm starting to attempt to work on a rom hacking project I have, for that, I was going to download a engine called hg-engine-mega.
So I was attempting to download it via the github tutorial but they ask me to download a specific version of python that apparently doesn't exist anymore (?). Tried searching the solution for a few days but found nothing. Here's the command it's asked to do and what appears.
sudo apt-get install python3.7
Package python3.7 is not available, but is referred to by another package This may mean that the package is missing, has been obsolete, or is only available from another source.
E: Package 'python3.7' has no installation candidate
I've also tried to download it via the official site through the executable app, but it didn't seem to recognize it. If anyone could give me a hand I'd be really happy.
Edit: Problem solved :) Thanks a lot to everyone that commented. You guys rock.
Edit:
I am able to successfully download python 3.7 on my Windows
As commented by @CrazyChucky and @Brian
3.7.9 is the latest 3.7 python with pre-build Windows installers
https://www.python.org/downloads/release/python-379/
3.7.17 is the latest version with security patches. It contains gzipped and XZ compresses files.
https://www.python.org/downloads/release/python-3717/

If you really must use Python 3.7 (which, as you noted, has reached end-of-life), the most up-to-date version, with security patches, is 3.7.17.
Download either of the two files listed on that page (gzipped or xz compressed). They contain exactly the same source code, just compressed in two different formats. Open the archive you've downloaded, and follow the instructions in PCBuild/readme.txt in order to build and install Python from source.
If at all possible, please consider using a newer version of Python. At least just try 3.8 and see if the project you're working on functions correctly with it. Alternatively, see if you can find a more up-to-date version of whatever project you're trying to set up.
-----To install specific version 3.7 of python in Google Colab-----
!sudo apt-get install python3.7
!sudo apt-get update -y
!sudo update-alternatives --install /usr/bin/python3 python3
/usr/bin/python3.7 1
!sudo update-alternatives --config python3
Select the specific number for 3.7
#Now check the version it will be 3.7
!python --version
#After that to install pip use these commands
I used @M. Abdullah Fiaz but
-----To install specific version 3.7 of python in Google Colab-----
!sudo apt-get install python3.7
!sudo apt-get update -y
!sudo update-alternatives --install /usr/bin/python3 python3
/usr/bin/python3.7 1
!sudo update-alternatives --config python3
In "!sudo update-alternatives --config python3" I was being asked:
There are 3 choices for the alternative python3 (providing /usr/bin/python3).
Selection Path Priority Status
------------------------------------------------------------
* 0 /usr/bin/python3.10 2 auto mode
1 /usr/bin/python3.10 2 manual mode
2 /usr/bin/python3.7 2 manual mode
3 /usr/bin/python3.8 1 manual mode
Press <enter> to keep the current choice[*], or type selection number: update-alternatives:
" So I changed it to:
!sudo update-alternatives --config python3 <<< '2'