Fix “Sold Out” Issue on Shopify Store (Print-on-Demand)

I need a Shopify specialist to fix an issue where all my products are showing as “sold out”.

I am using:

Gelato (for apparel)
Printify (for other products)

These are print-on-demand products, so inventory should not block purchases.

What needs to be done:

Fix inventory settings so products are purchasable
Ensure “continue selling when out of stock” is enabled
Check Gelato and Printify product sync
Confirm all variants are active and working
Test add-to-cart and checkout

Important:
I need someone who has experience with Shopify + print-on-demand apps (Gelato or Printify).
You will be given collaborator access to my Shopify store.