rent tron energy
https://energydelegationtronpost.birchreport.com/posts/energy-delegation-tron-gains-attention-as-network-activity-increases
I was trying to send a USDT transaction on Tron but kept getting an 'out of energy' error, so I looked into renting TRON energy instead of buying it. Turns out, you can just pay a small fee to borrow energy for a single transfer, which saves you from having to freeze a bunch of TRX. It worked perfectly for my small transfer, and the fee was way cheaper than what I would have spent on buying energy outright.