OP is looking for an alternative to MS Authenticator. If this works as an alternative temporarily, they may still consider it worth it.
[I]t is not considered secure in the last few environments I have worked in
Yes, SMS 2FA is usually not secure due being vulnerable to SIM card swapping attacks, that’s why I explicitly recommended using a VOIP number, which would not be vulnerable to SIM card swapping attacks.
Your employer might use MS Authenticator but still let you do call or SMS 2FA. If you use a VOIP number, it won’t be vulnerable to SIM card swapping attacks.
The same people claiming that Hamas uses human shields in Gaza claimed the Taliban used human shields in Afghanistan, claimed Saddam used human shields in Iraq, claimed the Viet Cong used human shields in Vietnam, etc. It’s just a “Look what you made me do” excuse for the occupying force killing innocent people.