Hi Crain,
Once again. A BIG THANK YOU for your time and checking it!
It took me some time to install new Magento, change my IP records so I could generate let’s encrypt SSL for a domain name and finally register M2e Pro and link eBay account to it. All work fine.
I’m testing now GoDaddy SSL. I’m guessing that I couldn’t get eBay token because the site wasn’t secured. I installed the SSL later but it was too late. I’m going to contact guys from M2e pro if it is possible to rewind things back. I don’t want to migrate all products data, attributes, categories and such.
Pawel