file/app/Http/Middleware/BindFileModelMiddleware.php

<?php

namespace App\Http\Middleware;

use App\Models\File;
use Closure;
use Illuminate\Support\Str;
use Illuminate\Http\Request;

class BindFileModelMiddleware
{
    /**
     * Handle an incoming request.
     *
     * @param  \Illuminate\Http\Request  $request
     * @param  \Closure(\Illuminate\Http\Request): (\Illuminate\Http\Response|\Illuminate\Http\RedirectResponse)  $next
     * @return \Illuminate\Http\Response|\Illuminate\Http\RedirectResponse
     */
    public function handle(Request $request, Closure $next)
    {
        if ($request->route()->action['as'] == 'api.file.store') {
            if(is_null($request->file('file'))){
                app()->bind('file', function () use ($request) {
                    return File::find($request->file);
                });
            }
        }

        return $next($request);
    }
}