If TechClient.macOS stops being able to send keys (Send Both, Send User, Send Password) then these steps to update the privacy permissions are the first steps to try.
TLDR (TooLongDidn’tRead) : Remove the Settings -> Privacy -> Accessibility -> TechClient, Exit TechClient, Start TechClient, try to “send” again, and then allow the same permission.
Full Directions:
1. Stop TechClient on your mac using the menu (TechClient->Quite TechClient)

2. Open Settings on your mac

3. Scroll down on the left menu and select “Privacy & Security”

4. Select “Accessibility” on the right.

5. Select “TechClient” from the list on the right and then click the little minus symbol on the botton (-).

6. You should end up with a list that does not include the TechClient
7. Open the TechClient, and try to send a credential. This will open a permission request dialog.

8. Click “Open System Settings”

9. Turn on the slider on the “TechClient” line.

10. Sending should now work in the TechClient.