deposit-ERC20.js : eth_sendTransaction does not exist/

Am trying to execute the deposit-ERC20.js script

avaialbe at

I intend to transfer a token from Ropsten to Matic testnet3.
I have created a custom upgradable token and deployed it at both the networks

Now when I execute the script I get

Error: Returned error: The method eth_sendTransaction does not exist/is not available

And calling
gives me “RangeError: private key length is invalid”
I have re-checked my private key and it is fine.

Some pointer will be helpful.
And I hope I can use my own erc token

Replying to my own post:
to fix “RangeError: private key length is invalid” … prefix “0x” if missing

We can not deposit own tokens to the depositor contract
Seems like only 3 tokens are supported for this

Hey @vikram - you can use the form here to submit the request for mapping your own token.

thank you sir for post.