When you log in, if your extension remains in a “in progress” status and the signature does not appear, please follow these steps:
If you are using Outlook, disconnect from the extension to confirm your email from Outlook WEB.
Create an HTML signature on Hubspot. The extension replaces an existing signature; it does not create one. To work around this, you must therefore create an HTML signature on Hubspot and restart the extension.

Check whether you have several environments on Hubspot. If you have several, you must rename them with the terms sandbox or developer. Once this is done, restart the connection of your extension.