Let a slack app create slash commands for another app? (Custom -> Jira)

I am trying to automatically create a ticket every month in Jira. Jira has a slash command to create tickets, which I could use each month to create a ticket myself, but that would not be different than going to Jira and doing it myself.

I would like to have my custom slackbot send these slash commands on my behalf.

Problems so far:
I can’t seem to get the bot to activate a slash command even if it types something with a slash in it.
Jira slash command opens a modal to get more information, so it’s not just “/Jira create detailsdetailsdetails

Any other solutions to recurring tickets for Jira that doesn’t require a paid plugin are welcome as well.