Step 1: Open Google Duo on your Android phone or tablet.
Step 2: After selecting the contact you wish to block, select options.
Step 3: Select any one of the following from the Contact Options menu.
- Select Block User.
- Check the "Report as spam" box, if applicable.
- Tap Block and Report Abuse.
Choose the appropriate type of abuse:
- Phishing or fraud.
- Malware (distributed via links).
- Harassment or hateful content.
Step 4: Finally, tap on Block.
Note: You are not required to choose an abuse type or report it as spam in order to block or report abuse.