The previous version, Photoshop 2022 (version 23.x), is compatible with Catalina. You could attempt installing the trial version of the Photography Plan to see if it will sense that you have Catalina (15.7) and install Photoshop v23 instead of v24. If not, there does appear to be a way to install older versions of the CC apps through the Adobe Creative Cloud app; you will need to create an account (free) to get there.