Problem with "you need to add a GTIN or MPN"

Hey, @Grace_01 !

​If you want to see how your ad appears in search results, it’s better to use the Ad Preview and Diagnosis tool rather than to do a search on Google. You’ll see the exact same results as a Google search but it won’t affect your performance stats by accumulating ad impressions every time you search for your ad.

To use the Ad Preview and Diagnosis tool, click the tools icon at the top right of your Google Ads account then click on Ad Preview and Diagnosis under the Planning section. You can also go right to google.com/AdPreview:

If you’re looking to become more confident with investing in Google Ads to grow your business, I recommend checking out this Shopify Compass course where you’ll learn the step-by-step process to launch three different Google Ads campaigns. Shopify Compass provides you with webinars and courses on things like store design, marketing, and more. It’s 100% free for everyone and new content is being added all the time. This program will help you drive more traffic into your store and also convert that traffic into sales.

I do hope this helps!