Go to Microsoft Ads and login to your account.

Select Tools

Select UET Tag

Select the UET Tag for the site you plan to place it on.

Select Copy.

Copy the code in the pop up window.

Now head over to your Wix site and login to the admin area.

Select your site

Select Settings

Scroll down to Advanced

Select Custom code

Select Add Custom Code

Under the Code Settings Tab

Paste the UET code into Paste the code snippet here box

For Name, enter Microsoft Ads UET Tag

For Add Code to Pages: Select All pages and set to load code once

For Place Code in: select Head

Select Apply

Select the other tab Code Type

Select the Marketing option

Select Apply

You can now close the window