Some apps show as incompatible with my tablet (Lenovo Y700 Gen 2) even though they work fine. I can often share those from my phone directly in the Play Store.
The article says I could use Files going forward, but it doesn't work - Quick Share is missing entirely on the tablet and I haven't found a way to enable/install it
While I haven't tested these extensively, you could give them a try (both are foss):
SD Maid SE: App Control > Export App
Kvaesitso: long tap > 3 dot menu > Share app
First one is designed for managing / cleaning up app storage. Second one is a launcher, so it might be a bit janky if all you need to do is transfer an app