once you purchased Office 2019, that is yours completely and you can transfer that licence any time you need and it will cost you nothing . . .
You need to deactivate your previous Installation and then re-install Office 2019
On the New Laptop, go to https://office.com/myaccount and sign in using your Microsoft account, if prompted
Select Install
Under Install information, locate the old Laptop which Office was installed on
Select Deactivate Install to deactivate the Office installation
Then, click Install to install Office