Domain Transfer
Previously, I purchased domains from NameCheap and GODaddy. As they both doing promotion all the time, the cost is next to nothing. But it is only true for the 1st year of domain hosting. Their hosting fee will jump up dramatically after that.
Lock up period
Because of this, I did some research about how to transfer domain from GoDaddy to Cloudflare. It is found that there is a 60 days lock up period after the domain purchase. That means I got to wait for awhile.
Other than money
Another reason for the domain transfer is that using Cloudflare CDN service seem to be a bit easilier the domain is hosted under Cloudflare. No matter what, I just tried to add the domain from NameCheap to Cloudflare.
After following the setup, it took around a hour for the Cloudflare to update the status. Seem most of those entries that previously under NameCheap is now working except for the Onlyoffice Mail which may need to reconfigure.