A variety of bus companies operate from Lo Pagan to various locations.
Bus stops to all destinations are all located about 2 mins walk from apartment.  See below.

There are different bus companies offering different levels of service
MOVIBUS operates the local short bus services  between local small towns (< 1 hour)
BAMBUS operates longer routes between regional cities  ALICANTE and CARTAGENA   .. (>1 hour away)
INTERBUS  operates direct bus service to  MURCIA city
ALSA operates direct services to MADRID (5 hours away)
BILMAN bus  operates Bus services to northwest of Spain

MOVIBUS operates local bus service for San Pedro Town and Santiago Ribera Town
L-V  is Mon to Fri ,  
is Sat
D y Fest  is Sunday and Bank Holidays
Link to Local Bus Routes   HERE

Bus top 8    in front of Café Roses/Jose Antonia  takes you to CARTAGENA

BAMBUS operate a regular direct AIRPORT bus service between ALICANTE airport and Lo Pagan. 
Bus arrives 10 to 15min after leaving Alicante City
Currently there are 3 buses Mon to Sat : 07:10  , 12:10 ,  17:10,
and two buses on a Sunday 09:10  and  17:10
NOTE: Timetable changes frequently.

Latest time table is here

In Lo Pagan you can catch the bus at these locations
Bus stop 11   on other side of road goes to ALICANTE  (Collection point for going to airport)

INTERBUS  connects San Pedro with Murcia City, again there is a bus stop
MURCIA. INTERBÚS
Tickets on the bus .  daily departures.
SAN PEDRO – MURCIA:
7.05 – 9.15– 11.04 – 13.35 – 15.15- 17.19 – 19.54 – 21.35
MURCIA – SAN PEDRO:
7.00 – 9.00 – 11.30 – 13.00- 15.15 – 17.15 – 19.30 – 21.30

Latest Local bus information locally can be found on this website
Goto Others Download and then select  TRANSPORTE  document
https://turismo.sanjavier.es/en/information/

The bus to MURCIA AIRPORT is suspended at the moment.  But there is an option to travel to Murcia City Bus station and collect a connection to the airport that runs 3 times a day. Airport bus goes from Bus stop 16  in the bus station.