Telegram bot API can only send files less than 20 MB by url
param, you should lookup Sending Files section.
If you want to send 20-50 MB files, you should download and re-upload to Telegram bot API server.
You can refer this simple code
$curl = curl_init();
curl_setopt_array($curl, [
CURLOPT_URL => 'https://api.telegram.org/bot131210513:AXXXXXX/sendDocument?caption=Hello+World&chat_id=24523586',
CURLOPT_RETURNTRANSFER => true,
CURLOPT_HTTPHEADER => [
'Content-Type: multipart/form-data'
],
CURLOPT_POST => true,
CURLOPT_POSTFIELDS => [
'document' => curl_file_create('/etc/hosts', 'plain/text', 'Hosts-file.txt')
]
]);
$data = curl_exec($curl);
curl_close($curl);