Postgres increase of configurations

Question

I need to increase the following settings for my postgres template. How can we do that since a SELECT pg_reload_conf(); does not work-- Connections (currently ~100, increase significantly)
ALTER SYSTEM SET max_connections = 500;

-- Memory allocation (from 280MB, use more)
ALTER SYSTEM SET shared_buffers = '8GB';           -- 25% of RAM
ALTER SYSTEM SET effective_cache_size = '24GB';   -- 75% of RAM
ALTER SYSTEM SET work_mem = '32MB';               -- 24GB / (500 connections × 1.5)
ALTER SYSTEM SET maintenance_work_mem = '2GB';   -- For VACUUM, CREATE INDEX

-- Query optimization
ALTER SYSTEM SET random_page_cost = 1.1;          -- For SSD
ALTER SYSTEM SET effective_io_concurrency = 200;  -- Multiple spindles
ALTER SYSTEM SET max_parallel_workers_per_gather = 4;
ALTER SYSTEM SET max_parallel_workers = 8;