The VAT payment details report provides the payment information you have made to HMRC. Select the VAT period and click 'Retrieve'.Your MTD app fetches the payment details from HMRC and will display it to you.

Steps on how to view my VAT Payment Details : 

After signing in to MTDVAT, you can see a page containing your e-file  data of your VAT returns. Then, please follow the below steps:
Step 1. Tap on the "Payments" button
Step 2. Now a page opens, which contains all your Payments history with "Traders Name" and "VAT Reg. No:".
Step 3. Under the "Traders Name" and "VAT Reg. No:", you can see an option  "TAX Year"  and "VAT Period ". 
Step 4. Now, you can select on which year you want the payment details by clicking on "TAX Year" , "VAT Period " and then on "Retrieve".
Step 5. After clicking on retrieve, it shows all the payment details of your VAT returns on the same page.
Step 6. Now, you can either view it or download it.

RoadMap on how to view Payments Details: Open the E-file data of your VAT Returns -> Tap on "Payments" button -> Select the date by clicking on "TAX Year" and "VAT Period" -> Click on "Retrieve" -> Now you can either view or download it.

Here's a video on how to view Payament Details :