Thank you fpr the clarification.
If the domain is always in pending status in Cloudflare, you have not correctly set the nameservers at your domain registrar. It is imperative that the only nameservers assigend at the registrar are the two nameservers shown in your Cloudflare account for that domain. No other nameservers shouldnbe present at the registrar.
NOTE: They may not be the same names that are assigned to other domains in your Cloudflare account.
If you share your domain name, someone from the Community will check the nameservers assigned at your registrar.