Why is the services.mygateway.gov.bs website not allowing you not create an account? It may be because there is already an account registered with your information. 

So, you'll need to sign in using the email and password chosen during the sign-up process. If you cannot remember your password, you can follow the steps below to reset your password:
Step 1: Visit services.mygateway.gov.bs.
Step 2: Select "forgot password"
Step 3: Enter in your email.
Step 4: Click "Send".
 Step 5: Go to your email and select the reset password email that would've been sent. Be sure to check you spam/junk email as well.
Step 6: You would click "Reset my Password" button that can be found in the email.
Step 7: Enter in the password of your choice. Twice.
Step 8: Select "Update"
Step 9: You will go back to the services.mygateway.gov.bs website and sign in using the email and password.
 
Please keep in mind that if you do not receive an email, it may be that the email you entered is not the email attached to your account. 

(Gmail Users) If sign-up error continues contact technical support.