You can purchase tickets from The Southport Bijou Cinema.
Either in person at:
The Bijou is a refurbished 1894 house. If you’re cycling, you can park in the alley. If you’re walking, the train station is 5 minutes away and buses go along Lord Street. If you’re driving, you can drop off friends outside the Bijou (turn left from Lord Street to St. George’s Place – go past Sainsbury’s then take the first left again). For matinees, it’s easy to use the Park and Ride service as the PR1 bus goes down Lord Street. After 6PM, street parking is free.
Or from their website here.