Hi @ValdasVelicka ,
The goal is to create and save the "QR code" for each SharePoint list item. Based on the requirements, I created the flow in my environment, please review and give it a try.
//Solution
1. Create a new Column in SharePoint List with name "QRCode" of Type "Hyperlink".
2. Create a Power automate flow by using the following steps:
//Please see Full flow below:

Step 1: Add a Trigger "When an item is created" and select the SharePoint Site and List form the Dropdown.

Step 2: Add a "Compose" action and paste the following URL.
https://chart.googleapis.com/chart?cht=qr&chs=150x150&chl=https://[YourOrganization].sharepoint.com/sites/[YourSiteName]/Lists/[YourListName]/DispForm.aspx?ID=
> Please make sure to replace the [YourOrganization], [YourSiteName] and [YourListName] with your organisation, site and list name. You can find these values from your SharePoint List URL.
> After the URL, please select the "ID" from the dynamic content.
> Please make sure that URL doesn't have any "empty space" and Final URL will be Looks like this. Please refer to following image:

Note: We can also use "Link to item" instead of this custom URL in "Compose," but due to the 255-character limit of the "Hyperlink" type column, we aren't going to use that.
Step 3: Add an "Update item" action. Then Add the Site address, List name from the dropdown, and Select id= "ID" and "QRCode" = "Output of Compose" from the Dynamic content. Please refer to below image:

Now, Save the flow and create new item in the SharePoint List. Please don't add anything in the "QRCode" Column.

After few seconds, you will see that a link in the QR-code Column is automatically added.

Now, go to List settings > Select the "QRCode" Column and change the "Format URL as" from "Hyperlink" to "Picture" and click on "OK" to Save.


After doing so, A "QR-Code" picture (instead of link) will appear in the column.
//Output

I hope it will help you.
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Thank you,
Harsh Deol