Linux LFTP connecting and mirroring folder over FTPS without certificate verification on Bitbucket pipelines

I've been trying to deploy my destination folder via Bitbucket pipelines and lftp for quite a while now. I've tried various variations of the Linux commands and have gone through a couple of dozen articles on the issue, yet I still can't get the thing to work.

So far, my pipeline commands look like this:

  - apt-get update
  - apt-get install lftp
  - lftp set ssl:verify-certificate no
  - lftp $FTP_HOST
  - user $FTP_USER
  - $FTP_PASSWORD
  - ls
  - quit

But for set, I'm getting 'lftp: set: Name or service not known' -- when I delete the step it gets to user, and I'm getting bash: user: command not found. If I add lftp in front of it, I'm getting lftp: user: Name or service not known

I think in total I've tried over 30+ times to get these right without any luck. How can I fix it?

I don't have any complete solution as I don't know Bitbucket, but I see clearly one mistake:

You cannot change lftp settings in subsequent command calls. That's what you are actually doing:

1. You invoke lftp with wrong command line arguments, set ssl:verify-certificate no.
2. lftp quits with error message set: Name or service not known. Even if you would have gotten the setting inside lftp in step 1, it would be cleared now because of the quit.
3. You invoke lftp with (probably) right command line argument '$FTP_HOST'.
4. Now 'lftp' quits, probably because it doesn't get any commands on standard input.
5. You mean to go all the other commands (user, password, ls, and quit) to go to lftp as standard input, but according to the logs, they are treated as further shell commands.

So please look at how to send standard input to a program with Bitbucket. (For information on standard input: it is referred to as "input" in following tutorial which explains how shell works: 1.3. Executing commands)