Follow the steps below or watch video
Signature installation steps
Open Outlook on the web and click on the gear icon in the top right corner. Choose "View all Outlook settings" from the drop-down menu.3
Select "Email" from the left-side menu and click "Compose and reply". You should see the "Email signature" section.4
Click "New signature", insert a name and paste your signature into the text field.5
Scroll down to the "Select default signatures" section and choose your newly created signature. Make sure to set "HTML" as the message format.6
In order to check your new signature, create a new email. You should see your signature in the message draft.