Follow these steps
Step 1:
Click on your Profile Name from the top-right hand side.
Step 2:
Select Profile & Settings.
Step 3:
From the left-hand side menu, click on Subscription.
Step 4:
Click on the Invoice History tab from the top-left hand side.
Step 5:
Locate the invoice you want to download.
Step 6:
Click on the download icon next to the respective invoice to download it.
If you have purchased an SMS add-on package, the invoice for this purchase will be available separately under the SMS Integration section.
Steps to Download SMS Invoices
Step 1:
Click on Profile & Settings.
Step 2:
From the left-hand side menu, click on SMS Integration below the Subscription tab.
Step 3:
Click on the SMS Invoice History tab.
Step 4:
Locate the invoice you want to download and click on the download icon next to it.