Your free option could be:
For apple - Photone - Grow Light Meter
https://apps.apple.com/us/app/photone-grow-light-meter/id1450079523
Android - PPFD Meter - Grow Light Meter
https://play.google.com/store/apps/details?id=com.homestudio.ppfdmeter&hl=en_GB&gl=US
Paid option for cheap price- Par Meter Wide Range Widely Used Digital Light Meter - China
https://www.ebay.co.uk/itm/325379512620?chn=ps&_trkparms=ispr%3D1&amdata=enc%3A1OpzHhidoR2OdjUqNgi4kyg24&norover=1&mkevt=1&mkrid=710-134428-41853-0&mkcid=2&mkscid=101&itemid=325379512620&targetid=1647205088280&device=c&mktype=pla&googleloc=9046691&poi=&campaignid=17206177401&mkgroupid=136851690655&rlsatarget=pla-1647205088280&abcId=9300866&merchantid=138361963&gclid=CjwKCAiAmuKbBhA2EiwAxQnt7wu0_DuG668sOE7qtNuWo6-FGQLg3LpC4sxvau2QD1_LT66JeBg7FBoCZk8QAvD_BwE
Paid option for high price - Quantum PAR Meter
https://www.amazon.co.uk/Quantum-PAR-Meter-Precision-Rechargeable/dp/B08JRPQ4L6
If you have good phone the free app are prety good and I have PAR and LUX meter and the reading are almost same when I use Samsung Galaxy s8 and the APP so dont waste you money like me and try the free APP first 😊👊👍