Warnings in Search Console - How to deal with?

[Mr_Bach]

I have got an email from Google Search Console telling me about registered issues in my spreadshop.

TeeShirters

Here is the announcement in Danish and Google Translate English:
Primære advarsler
Advarsler er forslag til forbedringer. Nogle advarsler kan hjælpe dig med at opnå en bedre placering i søgeresultaterne, og visse advarsler kan udvikle sig til deciderede fejl senere hen. Der blev registreret følgende advarsler på dit website:

Der er ikke angivet noget globalt anerkendt id-nummer (f.eks. gtin, mpn, isbn)
Feltet “priceValidUntil” mangler
Feltet “review” mangler
Feltet “sku” mangler
Vi anbefaler, at du løser disse problemer hurtigst muligt for at få den bedste oplevelse og dækning i Google Søgning.

And the Google announcement translated to English (Google translate):
Primary warnings

Warnings are suggestions for improvement. Some warnings may help you to get better rankings in the search results, and some warnings may develop into definite errors later. The following warnings were recorded on your site:

No globally recognized ID number (e.g., gtin, mpn, isbn) is specified
The “price valid until” field is missing
The “review” field is missing
The “Shoe” field is missing

We recommend resolving these issues as soon as possible to get the best experience and coverage on Google Search.

I have no idea how to solve this.
Need some help.
Niels

[Thomas_Spreadshop]

Hello Niels!
Please read that message carefully. As the mail says it clear:

Warnings are suggestions for improvement. Some warnings may help you to get better rankings in the search results, and some warnings may develop into definite errors later.

The information is followed by a list of IDs that are generally used in e-commerce shopsystems with stocked goods.
“price valid until” only applies for temporary offers or limited editions.
“review” fields are only valid, if a shop system has a rating or review functionality. (e.g. Google Reviews)
“Shoe” field is for shoe products.

As the spreadsshop does not offer any of these features, Google marks them as missing.
You can ignore that warning

stay safe!
Thomas