My misunderstanding the statement, it is actually 3V. please ignore the ticket
Is it possible to power the PCB with 3.7 VDC?
Yes, but running from a power supply which is constantly at 3.7V, such as a LiPo battery that is being kept topped-up by a solar panel, may shorten the lifespan of the system. The recommendation is to keep the voltage under 3.6V with a LDO power regulator such as a TPS71533.