run migration via rails console

irb_console_db_migration.txt

[6] pry(main)>  require "./db/migrate/20201216202520_add_activity_logging_to_user.rb"
=> true
[2] pry(main)> AddActivityLoggingToUser.new.up
=> nil
[3] pry(main)> AddActivityLoggingToUser.up
=> nil
[4] pry(main)> AddActivityLoggingToUser.new.migrate(:up)
==  AddActivityLoggingToUser: migrating =======================================
-- add_column(:users, :last_login_from_ip_address, :string, {:default=>nil})
   (1.5ms)  ALTER TABLE "users" ADD "last_login_from_ip_address" character varying DEFAULT NULL
   -> 0.0025s
==  AddActivityLoggingToUser: migrated (0.0026s) ==============================

=> nil

________________________
in other words:
________________________
require "./db/migrate/20201216202520_add_activity_logging_to_user.rb"
AddActivityLoggingToUser.new.migrate(:up)