Changer Image in mockups photoshop. Need coder help me!

An automated process would need to use Photoshop Scripting for actions can not use the logic that would be needed to do the job. Action  only have conditional steps that can test a small set of document and layer conditions.  Also if the replacement images are not exactly the same aspect ratio, sizes and print resolution as the object in the template file you can not use a script that only has support for Replace content for Smart Object layers.  Like the script in the post above this one. You need a script that can edit the templates smart object layers  object to deal with the mismatch files sizes.  Which also means the template  objects must be  an object Photoshop supports.  It Can not be a smart object created using Place to place in files like Camera Raw Files  or vector files like a .SVG or .AI.  For those smart object layer object will open in ACR or an other application like Illustrator. 

All Script and Action have dependencies.  Template files must have a layer structure a script was designed to work on and may have other dependencies like mapping Alpha channels.  My mockup script can handle miss matched  sized in one of to ways. Fit the replacement to the object. Images that have the wrong Aspect ratio will not fill the object there will be borders on top and bottom or on both side.  Or the Scripts can fill the object with the replacement image content. Images with the wrong Aspect Ratio will loose some content from the top and bottom  or both sides.  My script will not distort images  to the object aspect ratio. I do not like distortion and would not know to mask the replacement image the script is editing to help out Adobe Content Aware Scale feature. Which also can not do a good job if the aspect ratio difference is large..  I don't support size distortion. A Smart object layer associated Layer transform may warp and distort the object for the mockup.  That Layer Transform is not change.  The smart object layer will be transformed just like the one in the template.

Free Photoshop Photo Collage and Mockup Toolkit 

Sounds pretty straight forward, you should be able to create an action to do what you want. 

https://graphicdesign.stackexchange.com/questions/17995/automate-replacement-of-smart-objects-in-photoshop

Smart Objects: https://helpx.adobe.com/photoshop/using/create-smart-objects.html

Here is a script:

https://graphicdesign.stackexchange.com/questions/92796/replacing-a-smart-object-in-bulk-with-photoshops-variable-data-or-scripts