metamask signing up

I am a first time Metamask user and i am tryig to integrate with Metamask and sign a transaction from my account. Submit the signed transaction later to ethereum utilizing my API implementation.
I need only signTransaction feature from Metamask.
However when i try to invoke the eth_signTransaction or web3.eth.personal.signTransaction methods i get the below error.

inpage.js:1 MetaMask - RPC Error: The method ‘eth_signTransaction’ does not exist / is not available. {code: -32601, message: “The method ‘eth_signTransaction’ does not exist / is not available.”, data: {…}}

Could you please advise how to utilize Metamask only for Signing Transactons.

Hi there.
Are you follow the documentations here RPC API | MetaMask Docs ?

Where do i begin please help I put money on oap
How do I see my transaction

Sorry, I am not familiar with oap. Are you just looking to use MetaMask to make a transaction or are you developing something with MetaMask?

Oap is a bitcoin and they are using metamask

I made a transaction on metamask