Check with your domain registrar to configure your CNAME. Below are a few helpful docs for common registrars to get you started.
- Google domains: https://support.google.com/domains/answer/9211383?hl=en
- GoDaddy: https://www.godaddy.com/help/add-a-cname-record-19236
- Namecheap: https://www.namecheap.com/support/knowledgebase/article.aspx/9646/2237/how-to-create-a-cname-record-for-your-domain
- Domain.com: https://www.domain.com/help/article/dns-management-how-to-update-cname-aliases
- DreamHost: https://help.dreamhost.com/hc/en-us/articles/215414867-How-do-I-add-custom-DNS-records-#CNAME_record
- Bluehost: https://my.bluehost.com/hosting/help/resource/714
- Hover: https://help.hover.com/hc/en-us/articles/217282457-Managing-DNS-records-#h_43dbccfb-a3d3-408b-bd6a-204dab1616cb
- Dynadot: https://www.dynadot.com/community/help/question/create-CNAME