To create a signature for emails in Outlook Web, follow these steps:

1. Sign in to your Outlook account in a web browser.
2. Click on the gear icon in the upper right corner to open the Settings menu.
3. Click on «View all Outlook settings» at the bottom of the Settings menu.
4. Select «Compose and reply» from the options on the left-hand side.
5. Scroll down to the «Email signature» section.
6. Enter the text you want to include in your signature in the text box provided. You can format the text using the options provided, including font size, color, and style.
7. Optionally, you can add an image to your signature by clicking on the image icon and uploading an image from your computer.
8. If you want your signature to appear automatically on all new emails you compose, make sure the «Automatically include my signature on new messages that I compose» option is selected.
9. Click «Save» to save your signature settings.

Your signature should now be set up and ready to use in your Outlook Web account.