This is the core problem with all of the "one weird trick" solutions to the national debt: the court is not Rumplestiltskin, and will not vanish into the night if you find the right sequence of magic words, and markets know this.
One does not "invoke" amendments. Sanders is calling for Biden to issue Treasury Bonds in excess of the statutory debt limit and to see if they hold up in court. Who wants to buy a bond that SCOTUS could, and probably would, invalidate?