Solr search from nested json (php)

I am using solr as my search engine
Saving data in this format

 "id":1,
 "status_id":1,
 "availability":[
      "{children=1, form_date=1726790400, adults=3}",
      "{children=1, form_date=1726099200, adults=9}"
 ],

Trying to fetch details based in from_date > timestamp and adult >= 9

i am new to SOLR

query which i tried is

availability:[from_date:1726790400]

this gives error as
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in solr data saved as

enter image description here

and the field type is text_general