If you are not able to see the keywords in the Google Search console, Matomo will not be able to import the keywords. Here is the explanation of what’s likely happening:
Your website may be running with HTTPS only or Google may send all search traffic to your HTTPS website, but maybe you have configured a HTTP property in Google Search Console. So if you have added http://your-website.com to Google Search Console, it won’t show you any traffic directed to https://your-website.com
So you likely need to add the https://your-website.com URL-prefix property to Search Console and configure Matomo to import that data.
Alternatively, as you can see in this Google documentation, you can add a Domain Property. A Domain property in Search console will Include all subdomains (m, www, and so on) and both protocols (HTTP, HTTPS).
-> We recommend to add your Domain property to Google Search Console (or alternatively add your URL-Prefix property starting with https://).
Could you try this and let us know if you can see your keywords in the Search Console?