Joplin local file sync error

i have got accident with dropbox sync… and an ignorance of usage of sync causes all notes lost on both linux and android joplin… (when one device notes deleted, the other also follow suit to sync (sync with deleted files)…

now that i have recovered the data back, i would like to export it, but got boxy issue, can’t tell where i should export to.

i want to sync to local file system, which i can have a grip of my sync files… safe (i think)
but got error. can someone point out what’s the wrong with the sync address ?