Unhappy fruit tree (Heaton NE6)

Have inherited a very unhappy fruit tree in our yard
Can't tell you what type of tree it is for sure but an identification app said plum
Not sure how long it has been in this pot for, but is definitely not thriving, only had about 5 leaves this summer and really needs to be planted in the ground
Is about 6ft
I need to keep the pot
For anyone interested please reply with why you want it and a rough description of where you can plant it in the ground, as I want to make sure it gets planted out