How to transfer erc20 tokens between wallets rinkeby

I have simple erc20 token contrct deployed to rinkeby( When i tried to trasfer some erc20 to another contract, there is an issue:

execution reverted: ERC20: transfer amount exceeds allowance

But i called increaseAllowance method from erc20 contract. What i’m doing wrong?

Sorry, I am not sure what you mean.
If you want to transfer token from your own wallet account to a contract by call one function in the contract, you should call token.approve(CONTRACT_ADDR, AMOUNT) at first, and then call that function in the contract to transfer you token.

If you want to transfer token from contractA to contractB, there should be a similar approve function in the contractA, such as:

function approve(uint256 amount) public onlyOwner {
    ERC20.approve(contractB, amount);

and then just like the case one, call the function in the contractB to transfer you token.

I hope I have made myself clear.

thanks, that is solution. My error is setting ERC20.approve for contractA