D7 Biometrics: who, when and where?

Hi. Forgive me if I have missed this info somewhere! For a married couple, both have to do biometrics together? i\In the country of application (Thailand in this case) at the Portugese Embassy, as part of pre-approval? Or at the SEF appointment in Portugal, so both travel to Portugal? Once there, can we just stay or must we return to Thailand and then come back if the residency is issued? Yes, I appear naive, so thanks for any advice.

Itā€™s a little difficult to respond to your question because you do not give detail of when you applied for the ARI/GV, nor indicate whether you have received pre-approval yet.
SEF seem to be going through late Dec 2021 applications/ early 2022 applications now and offering the main applicant an appointment slot without offering an appointment to others who are dependents in the application. To summarise, investors who applied 18 months ago are only now (ie in 2023) being invited for a biometric appointment, if the application has already received pre-approval.
If you have only recently applied to the GV program (ie 2022 or 2023 and have NOT yet received preapproval you may want to go through the most recent posts (ie 2023 posts) in this thread: Awaiting Pre-Approval (Stage 2).
If you have already received pre-approval it would be helpful to know when you applied (exact date/year) and when pre-approval was received (month/year). The thread relevant to those who have received pre-approval and are waiting for biometrics is here: Awaiting Biometrics (Stage 3). The last posts (ie 2023 posts) are worth reading to give you a sense of what to expect.

Hi. Kind of you to reply so promptly and helpfully. Perhaps I am putting the cart before the horse! In fact, we are just about to apply for NIFs and then, hopefully, open a joint bank account, so early days in the D7 process. I was just trying to get a sense of how the process works.

Apologies for wrongly assuming that your question was about the investment visa (Golden Visa), as biometrics for this is a lengthy, protracted process. Iā€™ve taken the liberty of changing the title of your post, so that somebody more knowledgeable about D7 can reply.
You may also want to use the search function to look for D7, to see if somebody has already provided an answer to your question.