can I use a phone charger to charge my macbook pro?

Practically speaking, NO.

Depending on the exact model, MacBook Pro needs a minimum about 65 Watts from a USB-C power delivery capable charger, closer to 100 Watts for the 16-in models, and a genuine Apple 140 Watts power adapter for fast charging.

iPhone charger is too low, and Apple advises Not to use a power adapter that is smaller than the one they issued.

You’ll need to use a USB-C PD (Power Delivery) capable charger (eg; Apple 20W USB-C Power Adapter). Depending on the wattage, it may be quite slow. (Applicable only for Macs with USB-C ports).