Access attribute from collection to api

Hi , i have collection like that

#items: array:3 [▼
    0 => App\Models\FileActivity {#1620 ▼
      #connection: "mysql"
      #table: "file_activities"
      #primaryKey: "id"
      #keyType: "int"
      +incrementing: true
      #with: []
      #withCount: []
      +preventsLazyLoading: false
      #perPage: 15
      +exists: true
      +wasRecentlyCreated: false
      #escapeWhenCastingToString: false
      #attributes: array:13 [▼
        "id" => 27
        "file_id" => null
        "employee_id" => null
        "user_id" => 1
        "name" => "Updated Client wReagandd Amos Gallegos Joyced  On Field firstname  By John Doe"
        "old" => "wReagand"
        "new" => "wReagandd"
        "note" => null
        "section" => "Client"
        "status" => 0
        "is_read" => 0
        "created_at" => "2022-09-14 01:07:51"
        "updated_at" => "2022-09-14 01:07:51"
      ]
      #original: array:13 [▶]
      #changes: []
      #casts: []
      #classCastCache: []
      #attributeCastCache: []
      #dates: []
      #dateFormat: null
      #appends: []
      #dispatchesEvents: []
      #observables: []
      #relations: []
      #touches: []
      +timestamps: true
      #hidden: []
      #visible: []
      #fillable: array:10 [▶]
      #guarded: array:1 [▶]
    }
    1 => App\Models\FileActivity {#1619 ▶}
    2 => App\Models\FileActivity {#1618 ▶}

and i added

  public function getReadTimeAttribute()
  {
    return Carbon::createFromTimeStamp(strtotime($this->attributes['created_at']))->diffForHumans();
  }

and i send it as api the api want to insert it like

${value.read_time}

with javascript , so there's way to visible it with api json like that with the data

0	
id	27
file_id	null
employee_id	null
user_id	1
name	"Updated Client wReagandd Amos Gallegos Joyced  On Field firstname  By John Doe"
old	"wReagand"
new	"wReagandd"
note	null
section	"Client"
status	0
is_read	0
created_at	"2022-09-13T23:07:51.000000Z"
updated_at	"2022-09-13T23:07:51.000000Z"
1	
id	28
file_id	null
employee_id	null
user_id	1
name	"Updated Client wReagandd Amos Gallegos Joyced  On Field password  By John Doe"
old	"y$vXcuSVuu2KyTNkexZp8WruC90C.AeT1J4lvtEQ58PUWLs1yF9GnBG"
new	"y$l/MMAddjoHG1oJBdswb1ReEQCYZfP6sQx17gBLFljhF9mIwbPDIcO"
note	null
section	"Client"
status	0
is_read	0
created_at	"2022-09-13T23:07:51.000000Z"
updated_at	"2022-09-13T23:07:51.000000Z"
2	
id	29
file_id	null
employee_id	null
user_id	1
name	"Updated Client wReagandd Amos Gallegos Joyced  On Field updated_at  By John Doe"
old	"2022-09-14 01:00:14"
new	"2022-09-14 01:07:51"
note	null
section	"Client"
status	0
is_read	0
created_at	"2022-09-13T23:07:51.000000Z"
updated_at	"2022-09-13T23:07:51.000000Z"