Hello my friends sorry im new in zenphoto i install my web sites
but in google search console mobile usability part give in this errors for all zenphoto pages.
1-Viewport not set
2-Text too small to read
3-Clickable elements too close together
im using Basic theme last version Version 1.5.7
Can you help me how can i fix this problems thnks to much

It means that Google considers the Zenphoto themes not to comply with their current standards.
More specifically, Google wants your site to be (also) designed for mobile use. Unfortunately, the current Zenphoto themes are not.
New themes are in the works however.
In the meantime you can try these themes:
zpBootstrap, zenji, libratus or zpbase

@fretzl Thnks very much for your information
frankly I was very surprised to hear that even 2020 new version basic tema is not enough for mobile designed
i like the basic tema is it possble to add some meta code like;

For make it responsive designed or do you thinking still not going to be enough or not let me change it ?

No, that code alone will not make the theme responsive.
You will need to re-design the theme and for that some basic understanding of HTML, PHP and CSS is required.
Please read our theming tutorial.

We can add those meta info as they don't harm. But as fretzl notes that alone will not make the theme responsive. That really requires a lot more work and is not that easy task if you are not familar with it at all.

Yes, it is rather bad that the includet themes except zpMobile are not responsive. But the included themes are internally already "deprecated" and will not recieve any responsive or other major updates by us anymore.

There will at leat one modern new theme replacing the basic theme. Probably there will not be more than two included themes in the future. Can't say when though.