Two-factor authentication, SMS confirmation, SMS forwarding, 1 phone per team. Are there solutions?

Question

SMS

Many services require confirmation by SMS to confirm transactions or authorization.
Let's say you are the owner of a business and entrusted work in some service (hosting, mail for a domain, etc) to your subordinate. Some operations require SMS confirmation.
If the employee is:
1) new and you still don’t know him well
2) remote
3) contractor
4) some other option
and you don’t want to transfer a SIM card to full use to him / him (so that services, new services are not imposed on this number etc.), you will have to send SMS for each action.
The situation is aggravated if you are at a meeting, on a business trip, turn off the phone.
Question: What is the solution for SMS monitoring by several persons?
ps Let's say there is no third party to delegate work, no contracts / agreements with criminal liability with a signature are not considered.

Answer 1

+ SMS to email: https://www.google.ru/search?q=sms+to+email

Answer 2

I see two simple options:
1) using a gateway that has api and pulling SMS to your own, closed service
(google "receiving sms gateway api" and "sim hosting receiving api sms")
2) A smartphone application that can send http when receiving a request with data from SMS to your own, closed service
And employees, to a closed service (where SMS will be stored) is allowed under certain conditions.
Unfortunately, I do not know a ready-made solution (but this does not mean that they do not exist). If there are programmers in the team, then any of the points can be implemented in a short period of time.