Any queries to the api.linkedin.com/v2/ return "Not enough permissions to access ..."

Use r_liteprofile instead of r_basicprofile during the first step of Authorization. This will solve your issue.

You need to request permissions from LinkedIn.

Now all requests to api.linkedin.com/v2/ successfully pass to me!

We received permissions (r_ad_campaigns and rw_organization) after request offer by address https://business.linkedin.com/marketing-solutions/marketing-partners/become-a-partner/marketing-developer-program

Leave a request at the address below and LinkedIn will answer you.

Good luck!