Yes, console is slow, therefor I want to do this in php to make the progress automatically.
Let's say I have 50,000 child addresses and how to sweep the balance(if any) to the first child address for spending it later?

Hi
With Electrum console.
we can run this command to get a child private key
You are connected to an ElectrumX 1.16.0 server.
>>> getprivatekeyforpath('m/0/1')
"p2wpkh:Ky4XXXXXXXXXXXXXXXXXXXXXXXX"
>>>
Can this be done in php?
Input are electrum seed(12 words) or master private key:zrpivAZ*********** and the derive path, 'm/0/1' in above example.
I can pay you for this in bitcoin, please quote.
Thanks for you time.

Electrum creates 20 addresses by default. I created an address at high index(about 50,000) by script and sent some bitcoin to the address.

The amount of bitcoin doesn't present in my account balance because electrum only searches for balance for the first 20 addresses(index 0-19).

I tried to change the gap_limit to 50000 to make electrum searching for more, but electrum got frozen for hours and unresponsive.

So how can I access the missing bitcoin? Than you in advance.