How to renew access token on any request using refresh token?

Question

JavaScript

In general, such a task arose, but I am not strong in backing, so I ask for help.

So I have both tokens stored on the client, I return them when I log in, and I put them in the store.
I send each request to the header access token
. I store the refresh token in the database.

I end up sending a request, reading access, then creating a new access.
1. Why is there a refresh in this scheme? If you can just send a new access
2. How to send a new access in a normal request? Should I put it in req.header and change it on the client for every request?