How to transfer item from buydebug to inventory ?
Help me plz

Can you be more specific?
Are you talking about moving debug items into shared Family furniture inventory?

A number of the items that show up in the debug mod are meant only for the personal inventory of individual heroes, and should not be placed as furniture (It locks my system into an unending "loading" loop when I switch back to live-mode)
If you really want to try it for yourself, try to place and rotate the item into a diagonal. (Click and hold left mouse button, then drag in the direction you want it to face)

I wouldn't assume that any particular object is placeable in inventory, without a mod. What items can go where is controlled by flags on the object.

If you know what you're doing, you can certainly attempt to mod an item's flags, making it storeable, placeable etc. I don't know how closely TSM flags match TS3 flags, but the tools to look at the object data is there (S3PE opens TSM files).