Barium tagging is a future upgrade for nEXO (next-generation Enriched Xenon Observatory), a planned experiment that will search for neutrinoless double beta decay (0νββ) in ¹³⁶Xe. If detected, 0νββ would confirm that neutrinos are their own anti-particles and reveal their absolute masses. Due to the long half-life (>10²⁶ years) of 0νββ, a low background is critical to achieve the necessary detection sensitivity. Barium tagging is the ultimate method for rejecting 0νββ-like background events by confirming the production of ¹³⁶Ba as the daughter isotope of this decay. This can be done by extracting ions from the xenon detector, then identify barium through laser spectroscopy in a Linear Quadrupole Ion Trap (LQIT). The ions will then be sent to a Multi-reflection Time of Flight (MR-TOF) mass spectrometer, to distinguish ¹³⁶Ba from other naturally occurring barium isotopes as well as to identify other contaminants. The LQIT has been simulated and optimized to achieve high efficiencies in ion trapping and transmission. The development of the LQIT, from simulations to most recent experimental results of a prototype, will be presented.