Declared yes but kindly remember for the rent to be deductible, there are 5 conditions:
- company or branch must be registered at the address
- building must be registrable as company (see Where may I register my company?)
- rent must be paid from the company bank account
- contract must be under the company name
- all rent taxes must be paid (10% over 8.000.000VND per month) for 2020
No red invoices from the landlord is needed anymore.
Notarization is possible (if you wish to ensure the landlord is the landlord as the notary will require the pink book to be produced) but not mandatory.
You should be careful when signing a lease agreement and seek proper advice (see What is the best process to sign a lease agreement ?)