You must file Form I-90 (Application to Replace Permanent Resident Card) with USCIS.

After you file, USCIS will send you a receipt notice (Form I-797) that acts as temporary proof of your status.

While waiting, keep copies of your application receipt and any police report with you for protection.

If you urgently need proof of your status for work or travel, you can request an I-551 stamp in your passport from USCIS.