How to getheaders from blockchain? I have run a full node on linux
now I can run commands with bitcoin-cli like:

bitcoin-cli getbestblockhash


it returns:

0000000000344240308f54ded700542571b3df9efe05fab92e669099e20e0d92


or

bitcoin-cli getblockcount

82273


but I can't know where should I change get block to get headers: 

https://bitcoin.org/en/developer-reference#getheaders

I want to get all headers instead of total blocks to have a SVP node.
You can use the command bitcoin-cli getblockheader &quot;hash&quot; ( verbose ) to return a specific block header. For more info: bitcoin-cli help getblockheader

but I can't know where should I change get block to get headers: https://bitcoin.org/en/developer-reference#getheaders
I want to get all headers instead of total blocks to have a SVP node.

The getheaders message referenced in that link is part of the peer-to-peer gossip protocol between nodes, not the command line interface. From that link:

The getheaders message requests a headers message that provides block headers starting from a particular point in the block chain. It allows a peer which has been disconnected or started for the first time to get the headers it hasn’t seen yet.