Hi @Thanh Nguyen ,
Your user account doesn't have the necessary rights to purchase SendGrid,
message":"User failed validation to purchase resources.
If you're not the administrator of the subscription, I would say reach out to them to either purchase the Bronze level package or asked them to allow you Contributor or Owner role access; see https://learn.microsoft.com/en-us/azure/azure-resource-manager/management/resource-providers-and-types#register-resource-provider.
Do know that SendGrid only allows on service per subscription; see https://sendgrid.com/docs/for-developers/partners/microsoft-azure/ for additional details. If you happen to be in an Owner/Contributor role and are still having issues, comment down below.
Regards,
Ryan