Properly implemented no you would never do that, you would use a trusted SAML auth server to Authentication with your Domain Creds,
Something like Azure AD, ADFS, or 3rd party (that you assume to trust) like OneLogin. In all cases you would never enter your password into the SaaS service you are redirected to a secure portal controlled by the Auth Service, a token is then issued back to the SaaS service
Further it would be recommended not to use an elevated account and certainly not something like a Domain Admin account for those services
Something like Azure AD, ADFS, or 3rd party (that you assume to trust) like OneLogin. In all cases you would never enter your password into the SaaS service you are redirected to a secure portal controlled by the Auth Service, a token is then issued back to the SaaS service
Further it would be recommended not to use an elevated account and certainly not something like a Domain Admin account for those services