jfa-go can send notifications through Discord. You can also require it on sign-up to add a verification layer to the sign-up process for your server.
To do this, you'll need to create a Discord bot.
1: Create an application
Visit discord.com/developers and log in. Press the "New Application" Button, enter a name, and press "Create".
2: Go to the Bot tab
You can leave the settings on this page alone. Open the side menu (if necessary), and open the "Bot" tab.
3: Create the Bot
Press the "Add Bot" button, and "Yes, do it!" to create the bot.
4: Enable privileged permissions
jfa-go needs the privileged intent "Server Members" to present a list of users when you try to bind an existing Jellyfin account to a Discord one. Scroll down on the bot summary page to the "Privileged Gateway Intents" section, enable the "Server Members Intent", then press "Save Changes" when it pops up.
5: Switch to the OAuth2 Tab
Open the side menu (if necessary), and open the "OAuth2" tab.
6: Enable permissions, get Invite link
Scroll down the page to the "Scopes" section, and check all the checkboxes shown below. Once done, press the "Copy" button to copy the link. Visit the link to add the bot to your desired Discord server.
7: Copy the token
Switch back to the "Bot" tab, and press the "Copy" button to copy the bot token. In jfa-go, go to Settings > Telegram, enable it, and paste the token into the "API Token" box. Save and restart.