What is wrong with this datapack?

Hi, I've created a simple datapack for minecraft version 1.19.3 that gives all players the speed effect and also types a welcome message in chat upon loading. When i put this datapack into the datapacks folder of a world, load the world and type /reload in chat, nothing happens. I do not receive the speed effect, and the welcome message isn't shown. Why is this? What have i done wrong? I couldn't link the datapack to this post, so I've summarised it below: - Everything is stored inside a folder called datapack111 - Inside datapack111, there is a file called pack.mcmeta. Its contents are: { "pack": { "pack_format": 10, "description": "For use in superflat survival" } } - Inside datapack111, there is a folder called data. - Inside data there are two folders: 'minecraft' and '1A2B3C'. - Inside 1A2B3C there is a folder called functions, inside of which there are two files: load.mcfunction and tick.mcfunction. - Contents of load.mcfunction: tellraw @a {"text":"Datapack is working!"} - Contents of tick.mcfunction: effect give @a minecraft:speed 999 99 true - Inside the 'minecraft' folder there is a 'tags' folder, inside of which there is a 'functions' folder. - Inside the 'functions' folder there are two files, called load.json and tick.json. - Contents of load.json: { "values": [ "1A2B3C:load" ] } - Contents of tick.json: { "values": [ "1A2B3C:tick" ] }