Hi @atcasanova welcome to the community.
When sending native tokens you always need to include some ADA. As per the protocol rules it is not possible to have only non-ADA tokens being part of a UTXO. There must always be some ADA.
Please see following links:
Token deposit:
https://github.com/Emurgo/yoroi-frontend/blob/0038bc0afc5066904c59f376bef56c5e8581c4f7/docs/readme/cardano-token-deposit-explained.md
Minimum ADA requirement:
https://docs.cardano.org/native-tokens/minimum-ada-value-requirement
Online min ADA calculator:
https://mantis.functionally.io/how-to/min-ada-value/