Hello @vovangud, Thanks for getting in touch with us.
From what I gather, you’re looking to create a custom tab on the vendor store page to display the custom fields added by the vendor. However, with the MultiVendorX Pro(https://multivendorx.com/pricing/) ACF module, custom fields can only be added on the edit product page within the vendor dashboard and cannot be displayed elsewhere.
Since you’re interested in adding a custom tab to the store page, you will have to do that by adding custom code on your end.
If you want we can assist you by providing required hook/filter for this modification.
Looking forward to hear back from you soon.