As others have said, it's EXTREMELY frustrating when the IRS tells you that you must use an exact revision of a form and then doesn't make it available anywhere on their web site.

Here is where the Internet Archive Wayback Machine (https://web.archive.org/) is your friend. I noticed that the current link to Form 941 doesn't have any revision information (https://www.irs.gov/pub/irs-pdf/f941.pdf), which I hoped meant that it was their link to the latest version of the form. The link never changes but the document that is downloaded changes over time. By using the Wayback Machine I was able to look at previous versions of the web page and thus was able to find the earlier revisions of form 941 that I needed.

For 941 Rev April 2020 (for Q2 2020) go to the July 10, 2020 version of the link here: https://web.archive.org/web/20200710065611/https://www.irs.gov/pub/irs-pdf/f941.pdf

For 941 Rev. January 2020 go here: https://web.archive.org/web/20200407161422/https://www.irs.gov/pub/irs-pdf/f941.pdf