There is no Phoca Gallery image module in Joomla 4 yet. But that doesn't mean that you can't display Phoca Gallery images in Joomla modules.
To display images in the module, Phoca Gallery Content plugin will help us:
1) Install Phoca Gallery component.
2) Install Phoca Gallery Content plugin and publish it.
3) Then go to the Joomla administration and create a new module of type Custom (System - Site Modules - New - Custom).
4) Make sure Prepare Content parameter is enabled in the module. Fill in the module position and paste the Phoca Gallery Content plugin code here.
5) Save and publish. Now the images from Phoca Gallery will be displayed in the module.
