How to add track tags into single FLAC

I have multiple single FLAC files (album), how to add track tags into each single FLAC file so they can show up all the tracks in each album in f2k? Right now those only show up as '01 track name' (tried to use mp3tag once). Others all show up with their own file names.

*I noticed some single FLAC files show up correct sub-tracks in f2k.

I am pretty new to mp3tag ( my first tag software). Please feel free to ask me more questions if I miss any details.

Thank you.

How do you know which title a file represents?
If the title is part of the filename then it could be possible to import that data from the filename with Converter>Filename-Tag

The title of each flac file has the basic information (artist, album name), it is my fault to delete the .cue file in my NAS.

I noticed the tag information I pulled from MusicBrainz has all the tracks information, I wonder if I can add them to my single flac file.

Where is that stored now? In a text file? Then it could be possible to retrieve data with Converter>Text file-Tag

No, I was trying to tag that single file with mp3tag, and trying to match information into the flac file I have. What is the converter you mention above?

Thank you for your patience.

The converter is a function in MP3tag - have a look at the menu "Converter" or slide along the toolbar until the bubble help shows the label of the corresponding button.

I managed to restore the deleted cue files from recycle bin in my NAS, but mp3tag cannot load the text inside the cue file.

There is a function in the File menu to open a cue sheet.

Thank you, now I can load the cue sheet, I suppose I can edit it from this point?

Anyway, I believe I am getting some progress at this point, and really appreciate you walk me to this point (in fact I am just super sleepy).

I will continue to work on this tomorrow. Thank you.