Simple, supply & demand. When there is more supply of money to spend, goods & services become in greater demand. That increased demand means more people to fulfill those demands resulting in hiring across many types of employment.
Increase in demand can be easily gained with exports.
Due to border adjustability, our exports would leave our shores without our tax costs built-in [as the costs currently ARE built-in]. That will make our exports cost less hence more demand for them.
Imports will become more expensive/have their profitability reduced b/c imports will have the tax added to their price. So their price will probably rise a little and their profitability will reduce a little [imports have been eating our lunch b/c they have systems to send us goods without tax costs.]