Look at your lease, it should have stipulations for showing the property if it is offered for sale.
If you have concerns, contact your owner, the contract and showing instructions are between the owner and the Realtor who listed the property for sale.
I think the first thing to is get with the person you leasing from and let them no what ’s going on.Because if you going to lease this build on one else sure be sale this build.So the best thing is to get a real estate lawyer to look into it ,it sure cost nothing.So before you go any far let some look at your paper work.Before you be out of your money and investment.GOOD LUCK!