Add to your project by executing:

npm install truffle-plugin-topup

Add the following to your truffle config (truffle-config.js or truffle.js):

plugins: ['truffle-plugin-topup']

truffle run ADDRESS [AMOUNT]

example:

truffle run 0xeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee 10 would topup account 0xeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee by 10 Ether. AMOUNT is optional and defaults to 10 Ether.