How can I access images made by Mapillary before I upload them?

I made recording using Mapillary on Android phone. As I understand after I upload images to server, they will be deleted from my phone.

I want to save those unprocessed images for other purpose. I cannot find them. Where images are located?

As I remember, images were accessible in one directory, but now that directory is nowhere to be found.

It is private to the app. Mapillary does not want you to have access to your own photos. And the security model of Android explicitly considers the phone owner and user as a threat and therefore gives the apps the opportunity to hide data from them.
Only if you have rooted your phone, you will be able to access that storage.

I read somewhere in this forum that the mapillary app might re-enable accessnat some pont, but since about 2020 there has been no change.

see lots of threads, e.g. Cannot access Mapillary photo storage on Android device via USB

This request makes sense to me - and we will add this to the backlog (making it possible for you to see the Mapillary images folder even for non-rooted devices). Thank you for the suggestion!