Final Cut Pro x and apple motion 5 compatible with Catalina
where to download previous version of these apps
Apple has apparently made some changes recently and does not offer older software versions of FCP and probably Motion too. It used to be that if you logged into the Apple Store with the Apple ID you used to originally purchase the software, then went to your previous purchases, you could download the last version that was compatible with your MacOS. It seems now you'll have to restore a copy from your backups.