No Log-In option on Google Photos App running under Fire TV Stick 4k

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Hi,
I have installed Google Photos via Sideloading on my Amazon Fire TV Stick 4k (like some other Android Apps as well). Note that I have downloaded the Google Photos APK file from "apkpure".

After launching the Google Photos App on the Fire TV Stick 4k I could not find any menu option to log in to Google Photos. There were only offered the following options in the top left corner of the App screen:
- Photos
- Recycle bin
- Settings
There were no additional options to select (Note that I am also using Mouse Toggle).

Said that is there any advice on how to log in to my Google Photos accunt under the above environment.

Thanks
fb03