Minecraft 1.14.2 functions not working

I am trying to make a function in Minecraft 1.14.2, and it just doesn't work. I tried everything and looked for answers everywhere, but it still doesn't work. I did the following:

• created a .mcfunction file in \<myWorldName>\datapacks\<dataPackName>\data\<nameSpace>\functions;
• saved it in UTF-8 without BOM (using Notepad++), and later tried ANSI;
• did /reload and then /function <nameSpace>:<functionName>. It always just writes "Unknown function <functionName>". It didn't work a single time.

My function file is very simple, I just try to test it with something like:

say 123

I really don't know what to do next, please, can you help me?

You also need "pack.mcmeta" in your <datapackName> folder. The wiki tells you what that can all contain, but the simplest case is just:

{"pack":{"pack_format":3,"description":""}}