I just have launched my pages a week ago(https://interior-and-furniture.myshopify.com)
and I tried to send xml file to Search console to be fetched several times ,but it shows: couldn`t fetched.
I assume this is because robots.txt status is disallowed.(https://interior-and-furniture.myshopify.com/robots.txt)
However, shopify support says you cannot edit robots.txt status.
this topic says need new primary domain to be crawled by google:
Is there any other way to crawled by google?
or Is there any other cause to prevent my pages from google crawling?
As you said, the reason is your robot.txt file disallows Google bots so that bots can not visit your URLs and as a result, your pages don't get indexed.
To solve this issue you should change your robot.txt to allow status. Also, this guide: How to get your online shop on Google would help your pages get indexed more quickly.
Hope it helps!