Why am I getting an 'Authenticate Error' during Salesforce Shopify sync setup?

[pramodastreait]

Hi

I installed this app for my small business but had certain issues while Salesforce shopify sync setting i complete step 1 and on step 2 i got the below error

"Authenticate Error or please check shopify self-signed certificate" while i have created selfSigned cetificate with name "Shopify" .

kindly plz help me.