As a single option for testing, NutriPATH offer Oxalate screening through either a spot urine or 24 hour urine collection. Oxalate is a natural end product of metabolism in the body. It should leave your body through your urine.
References:
Mitchell T, Kumar P, Reddy T, et al. Dietary oxalate and kidney stone formation. Am J Physiol Renal Physiol. 2019;316(3):F409-F413. doi:10.1152/ajprenal.00373.2018
Sadaf H, Raza SI, Hassan SW. Role of gut microbiota against calcium oxalate. Microb Pathog. 2017;109:287-291. doi:10.1016/j.micpath.2017.06.009