test/app/Http/Models/FlowStageTpl.php

<?php

namespace App\Http\Models;

use Illuminate\Database\Eloquent\Model;

class FlowStageTpl extends Model
{
    protected $primaryKey = 'id';
    protected $table = 'flow_stage_tpl';
    protected $guarded = [];

    public function infoTplList(){
        return $this->hasMany(FlowInfoTpl::class,'stage_id','id');
    }
}