herca, the only way I have found to do this is to modify the URLs below.
You MUST replace the "xxx" with your author and "yyy" with your keyword/search term.
FREE MODELS
https://www.cgtrader.com/free-3d-models?author=xxx&keywords=yyy
PAID MODELS
https://www.cgtrader.com/3d-models?author=xxx&keywords=yyy
so, for example, if I was looking for a free "switch" from the author "traceparts" I would edit the URL as follows:
https://www.cgtrader.com/free-3d-models?author=traceparts&keywords=switch
Then just copy and paste this URL into your browser's address bar.
ps. if you have more than 1 keyword/search term, you can separate them with commas.
for example:
If I wanted to search for "cam" and "switch" from the author "traceparts" I would use the following:
https://www.cgtrader.com/free-3d-models?author=traceparts&keywords=cam,switch
I hope this helps someone. Cheers!