Not Able to Insert Taxonomy Term Using wp_insert_post()

Few points come to mind:

1. There is a typo in "post_type" => "'eyeglasses" (extra single quote). It should be: "post_type" => "eyeglasses".

2. Try putting the $term instead of array( $term ):

   "tax_input" => array(
       "models" => $term
   )
   

3. Also, is it models or model? e.g.

   "tax_input" => array(
       "model" => $term
   )
   

4. tax_input requires assign_terms capability. So if the user you are running this CODE with, doesn’t have that capability, it’ll not work.

   In that case, the right way is:

   $post_id = wp_insert_post(array(
       "post_type" => "eyeglasses",
       "post_title" => $title,
       "post_status" => "publish"
   ));
   
   wp_set_object_terms( $post_id, $term, 'model' );