Hi @Remiswood, @wbkellam
Thanks for your question!
You'll want to contact your domain host support to be sure but as far as the steps from Shopify's support documents for adding the SPF record see below:
Add Shopify's SPF record to your TXT record:
v=spf1 include:shops.shopify.com ~all.
@or leave it blank.
v=spf1 include:shops.shopify.com ~all. If your domain host already has an SPF record, or you also need to add your email host provider's SPF record, then include all records between
The Host field can be left blank or you can add an "@" symbol. Let me know how that goes!