It can be downloaded from fdroid. However, ensure that you have the correct repo for it, which can be found on the "side bar" or the "about" section of this community. Here's the link for the repo: https://bazsalanszky.codeberg.page/fdroid/repo/

Depends on how you installed it originally.

If you installed via play store then try clicking on your icon, on the top right, then 'manage apps' and go to the update area, refresh and see if the update appears.

If you installed via fdroid (izzy's repo), then you will have to wait until it's available there.

If you installed it directly from codeberg, then I believe you will have to download and install the latest release. People tend to use the Obtainium app for this.

Hopefully this clears things up for you. And if I'm mistaken on something, my apologies.