Hi,
I assume you are aiming to control a relay with a rated voltage higher than 3.3 V, e.g. 12 V. If so, you would need an additional n-channel MOSFET or a npn BJT to control the PMOS, by means of its Gate-Source voltage. Have a look at Fig. 3 in [1]. Keep in mind, to turn the PMOS completely off (non-conductive), the Gate-Source voltage difference has to be 0 V. So for a 12 V voltage source (used to control the relay) which is connected to the source of the PMOS, also the Gate voltage has to be 12 V to turn the PMOS off.
https://www.onsemi.cn/PowerSolutions/document/AND9093-D.PDF
BR