If ss.phrineclothing.com subdomain used.
Just create new one that points only to 35.193.123.107 and don’t add any other records for this sub domain.
For example use:
gtm.phrineclothing.com
In case if gtm.phrineclothing.com CNAME record will be created automatically just delete it and leave only A record.
If you will still have difficulties with this you can ask Shopify for help create this record for you or move domain management to Cloudflare.