Problem with erpnext Shopify

I install ERPNEXT-Shopify from app installer , i use private key to connect erpnext to my online shop and try to synchronise , but for 5 days nothing happened , after 5 days i check yesterday one products imported to shopify but quantity in shopify is 0 , even quantity in erpnext is 7 , i chose option of Sync Quantity With Shopify .
i select other products to sync with shopify and try to synchronise ، but nothing happened ,item not added in shopify .
any one have experience to help us .

It will sync qty from warehouse specified on Shopify settings.

Did you/system manager get any email saying shopify sync has been stop or something?

i’t not sync with warehouse specified on shopify setting ,
no system manager also not get any email. do you have any idea what’s problem ?