Mockaroo is a great tool for getting realistic random data. So if you need to test big lists, with a huge amount of data and many columns, you can use their API to get records and put in the list.
I will show you how you can do it!
In first, we must have an account on Mockaroo web. After successful login in, go to the schemas tab and create a schema.
Next, on New Schema page, create your desired schema, I just used a default options. When you are ready, save schema by save as..., and save the name.
Next, go to the Mock API tab, in route set to the name of your schema, do the same in handler script form, set schema name:

Click crate mock api. Get the try in browser link:

Back to the Power Automate
In your solution, add a new Connection Reference, chose Mockaroo (Independent Publisher), add new connection. In the new page, set your API key from the link you copied:

This connection required the premium 💎 licence!
Usage Limits:
| Plan | Limit |
|---|---|
| Free | 200 requests/day |
| Silver | 1,000,000 records/day |
| Gold | 10,000,000 records/day |
Great, let’s test it in some flow.
In the new flow, just find Mockaroo action and set schema name with your schema you crated earlier:

Save, and test it, see if you get the date:

And… we get our JSON in output. Finish the flow to put that records in to SharePoint list:
After a while, our list gets all new brand items:



