Testing for lead in kids toys

I recently went down a rabbit hole about lead in toys sourced from places like Temu and Amazon, and I realized that shortly after my son was born I bought some toys, including teether toys/sensory books and a tummy time mat off of Amazon. Some of these were direct from the toy maker, but the tummy time mat and pillow were from a third party Chinese seller and I didn’t notice. Also we have been given some toys and I am not sure the source.

He’s 4 months old now and putting everything in his mouth. Should I quarantine these items? Is there any reliable way to test them for safety? I’m panicking a bit that I may have put my baby at risk.

Additionally my MIL loves Temu and I’d Iomega to gently but firmly discourage her from buying our baby anything from there going forward. Links or resources that I could share with her would be great.