This is Noah from PageFly - Shopify Page Builder App
Regards your concern. First, you will need to the enable the Customer setting from Shopify Admin.
It is in Shopify Settings > Customer Account > tick this option :
After that you can customize the default login icon like the screenshot you sent.
Hope this can help you solve the issue
Noah | PageFly
Please let me know if it works by giving it a Like or marking it as a solution!
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