EBay multi listing setup and Training

I am requesting assistance with the multi-upload process for listing multiple items on eBay. The goal is to efficiently upload and manage multiple product listings simultaneously.

Details of the work include:
Preparing data files (CSV or Excel) with item details such as titles, descriptions, prices, quantities, and images.
Ensuring proper formatting according to eBay's specifications.

Uploading the data via the eBay Seller Hub or API.
Verifying successful uploads and addressing any errors or issues.

Automating the process for future bulk uploads if possible.

Using our existing 1200 Product recovery to EBay

Provide clear guideline document how to upload if error happens again

We have all the data retrieve

Please let me know the timeline and any requirements or information needed from my side to proceed.

Thank you.