How to open/upload hidden files in apps or webapps? I can't view .DS_Store, .localized, ._.* and ._* with Finder: Show ALL files starting with a dot in Finder
user3439894 commented there that it's impossible to do so with Finder:

Some dot files, e.g. .DS_Store, you can see in Terminal using e.g. ls -a however the ones you used to see in Finder and cannot now see them is because Finder is programmed to not show those files files even with it's set to show hidden files. The ._* and ._.* are extended attributes/resource fork files and normally cannot be seen in Terminal or Finder when properly associated/linked to their normal files or if created on a filesystem which does support them and either viewed from Finder or brought back to an HFS+/APFS filesystem.

And an answer on SO Unable to show .DS_Store file on Mojave also says it's impossible with Finder.
So my question is, how can I send my handwritten file ._. to people on Discord?
I can't drag-and-drop the file to Discord, because I can't see it in Finder in the first place, and also the upload dialogue uses macOS' Finder file browser as most apps do so I also can't select the file manually after clicking the &quot;Browse...&quot; button.
Looking at your question, I can tell you that it is possible for you to create a file name &quot;._.&quot; and then share it however, discord will automatically change the filename when you upload. This is how you do it tough. First, open the terminal then type the command touch ._. then type open ._. this will open the file in the text editor. Once you have the file opened type whatever you want in there, once you are done, open discord, and then drag the blank file icon from your text editor into discord. However, as I said, there is no point because discord will change the file name.