E received a text from GSTCRA.com informing me that I have a GST rebate in April. Is this legitimate?

Doubt it. CRA is on canada.ca, and wouldn't text you anything. It's either direct deposit or letter mail

@Billyjohn75 We would suggest not opening any link sent via text without verifying the source (CRA). CRA usually sent information to your CRA My account and you will receive an email. You can also contact CRA directly to verify this information.