For the ISO download link, you can directly open https://setup.office.com
Type the previously purchased Activation Key in the box in the box as shown below.
When the activation process fails, it doesn't mean the Product Key is damaged, please go back and select "I want to activate the software by telephone" as shown below.
After that, please write the Installation ID in notepad for the next process.
Next, please open the link below. https://getcid.info/
TYPE the Installation ID in the Get Confirmation ID column as shown below
Next, copy the confirmation id that appears and then paste it in the product activation dialog box.
the product has been activated as shown below.