Want to attempt potty training but 2.5 yr old has constant constipation

[Fevs]

So I am pregnant and due to have another baby in March. I am keen to potty train my 2.5 yr old now so by the time the baby comes she is out of nappies.
I think she is ready but the problem is she has a constipation problem. I give her laxitive sachets (prescribed by the doctor) twice a day and have been for around 6 months. I’m told it’s really common in toddlers but have taken her to a specialist anyway - waiting on results from that. So it’s not a short term / temp problem it could be here for a while.
I can’t really wait for that to be resolved before I start with the training but am worried that she will find it even harder to poo on the potty then she does in her nappy and possibly hold it in more?
I’m sure once I start I’ll soon find out! But has anyone else potty trained their toddler who experiences regular constipation?
Any tips or advice that you can offer? Would be most grateful!
Thanks

Maybe it's worth just giving it a go and seeing how they get on? They may not worry about the potty? Use a distraction like watching some tv while on the potty? My little girl had constipation but was fine with going on the potty. She still has movicol daily at the moment but starting to look at coming off it. Not a lot of help as haven't had the problem as bad as you it seems but I know I appreciate at least some kind of response when I try something. Good Luck!!