In my case the green button for inserting the generated tokens into the settings page is working, but if you are having trouble with it, you should be able to insert it into the database in the table "_extensions", you search for the line with type=component and element=com_sppagebuilder, and in the column params of this row you see the parameters where you can insert the various ids.
In specific, in the following part:
{\"appId\":\"000000000\",\"appSecret\":\"00000000000\",\"accessToken\":\"00000000000000\",\"igId\":\"000000000000\"}