Step 1: Log into your CallHippo dialer https://dialer.callhippo.com/dial
Step 2: On the left-hand side of the dialer, tap the icon consisting of three horizontal lines, then select the 'All Calls/Inbox' section."
Step 3: Next, tap the forward arrow icon located next to the number you wish to blacklist within the 'All Calls/Inbox' section.
Step 4: Once you open the page an option with DNC is available on the right-hand side of the number where you will get three selections to block the number.
Step 5: After choosing the desired option a pop-up message will appear like the one below and the number will fall under the DNC list once you click on “YES”
I hope this was helpful
In case of any doubt please reach to support@callhippo.com