all coins will be mined in March 2021

I'm right?
If I read the code correctly, you are about right.
Mining reward will be zero in about 72.3 days from now.
https://github.com/Crypto-Currency/litebar/blob/master/src/main.cpp#L885-L896 :
int64 static GetBlockValue(int nHeight, int64 nFees)
{
int64 nSubsidy = 5 * COIN;
// first 15 days will dispose 5 coins per block = 7200 blocks (36000 coins)
if(nHeight>7200) nSubsidy = 2 * COIN;
// Hereafter, subsidy is cut in half every 438000 blocks, which will occur approximately every 2.5 years and end at year 5
nSubsidy >>= (nHeight / 438000);
return nSubsidy + nFees;
}
Given that it has not a shit ton of tx right now, the chain will probably get stuck then until enough tx fees have piled up to lure in a miner.