Hello. I work for Uber Eats as a delivery driver. My question is I notice they only give me some HST invoices. Does this have to do with interlining?

That is a very good question, one you should ask your employer.  

Drivers who earn with Uber Eats are only obligated to register, collect, and remit sales tax from the moment they reach $30,000 of revenue over the past 4 quarters.

This includes revenue you make on Uber rides, Uber Eats, and any other sources of business income.

Each individual's tax situation is different and could be impacted by earnings made outside of the Uber app.

If you are responsible to collect sales tax based on this threshold, you will need to provide Uber Eats your HST/GST registration number.