afaik it was Pauli; he studied the operator algebra of the Hydrogen atom which can be mapped to an SO(4) algebra generated by the angular momentum and the Lenz-Runge operator, from which the spectrum can be derived exactly; however this does not include the solution fort the wave functions
Schrödinger did it in 1926 too, his paper was received January 27. E. Schrödinger: „Quantisierung als Eigenwertproblem I“, Annalen der Physik 79 (1926).
It was Pauli, but it doesn't really matter, because the two methods could not have been any more different. It's just like the case of the <Einstein field equations> of GR which were first published by David Hilbert, but the derivation method was different than the method of Einstein.
So the issue of <who was first> is really not that important.