You can do this using ehsankia’s quote list CustomAPI - read more about it here.
What you do is click this link. It will generate three links and two tokens, a public token which will allow people to view the quote list and a private token (that you should keep to yourself) that allows you to edit the list. The public token is located within the first generated link. The private token is located within both the second and third generated links. The tokens are found after token= and before &data=$(querystring) Copy them and keep them somewhere safe!
Either copy and paste these commands as they are into your chat OR just copy the command responses and use the Nightbot dashboard to create the commands. Replace each PRIVATE_TOKEN with your private token and each PUBLIC_TOKEN with your public token before adding the commands.
IMPORTANT: It is safer to add the commands through the Nightbot dashboard. Add these commands through chat ONLY if you are sure no one else is in the chat, otherwise they might see your private token!
!addcom -cd=5 !recruitme $(urlfetch http://twitch.center/customapi/addquote?token=PRIVATE_TOKEN&data=$(user) - $(querystring))
!addcom -cd=5 !recruitlist Recruit list: http://twitch.center/customapi/quote/list?token=PUBLIC_TOKEN&no_id=1
!addcom -cd=5 -ul=mod !recruitclear $(urlfetch http://twitch.center/customapi/delquote?token=PRIVATE_TOKEN&clear=1)
!addcom -cd=5 -ul=mod !recruitdel $(urlfetch http://twitch.center/customapi/delquote?token=PRIVATE_TOKEN&data=$(querystring))
!recruitme is for viewers to use. When used, it will create an entry in the list that contains the user’s name and their request.
!recruitlist gives a link that shows the request list.
!recruitclear removes all entries from the list. I have set it up so it can only be used by moderators and up.
!recruitdel removes a specific entry from the list. You have to input a certain entry number or user that is on the list after the command. I have set it up to only be used to moderators and up.