Yes you are. The best source for D7 info is the document ‘2021 Visas and Permits’ found in the Files section of the ‘Americans & FriendsPT’ facebook group. The document is kept up to date. Quote from it:
Often referred to as a long-stay, passive income or resident visa, the D7 visa for those who are retired, not working (financially independent), self-employed (remote/digital nomads), employed/working remotely for a company outside of Portugal, or living on passive income from investments, real estate rentals, social security, pensions, and/or a business.