Sort of work dilemma re training

[BluebellBlueballs]

I took a job a year ago as a manager of a small HR team/function. At that time there was a role reporting in to me for a training manager, with an assistant reporting in to them. I don't have a training background, and this was made clear in interview.
That person left and due to cost cutting, the role was not replaced. I am now expected to pick up the 'senior' part of that role and the assistant the more junior elements. This is now becoming the focal point of the role and after being told we didn't need a training manager anymore, they have now tasked me with setting up a massive training programme. Well, I don't want to and it's not what I signed up for so I'm looking elsewhere and will jump ship as soon as I get something else. I also feel I can't properly manage the assistant as I don't have enough skills and knowledge to develop the work to then manage/develop/give them stuff.

Work are now saying they will put me on a training course to try and get some skills to write and deliver this training programme. I'll go on the training but I feel a bit bad that I probably won't get to put it in place as I'll be off as soon as I get an offer. Do I say anything or just keep my cards close to my chest until I am in a position to resign? I feel like I've been railroaded into accepting these new duties which until recently were someone else's job completely, and I just have to play along. I was never consulted on the changes or given any extra money for basically absorbing someone else's job into my own, there is enough of my old job left that it's not enough of a change to make my original role redundant - they have just added in the old job to mine as a cost saving measure.

[StopMindlesslyScrolling]

Do the course; it's always good to have additional strings to your bow when applying for other roles.

Explain in your exit interview the reasons why you're leaving; they offered you one job and expected you to do another and had you known that's what they wanted you never would have applied for the role in the first place.

Alternatively, roll the dice and explain that they're asking you do do something you weren't employed to do and you're not prepared to do the training, if they want someone for that role they need to hire someone in. Problem is that they may hire someone who can do the training job plus your role, so it depends on how secure you feel your job is.