How to define a FILTER ？

[lj4353]

I want to define a FILTER with the entity named Introductionfriend, filtering where paymentStatus == 'paid'.

[yuri]

In metadata > selectDefs > {EntityType}: https://docs.espocrm.com/development...erclassnamemap

In the filter, apply

$queryBuild->where(['paymentStatus' => 'paid']); 

[lj4353]

where can I find metadata ？