Power automate shows me the following error: In the "addDays" function, the value that has been provided for the datetime string isn´t valid. The datetime string must match ISO 8601 format.
The error ocurrs when the following control is executed:

Power automate shows me the following error: In the "addDays" function, the value that has been provided for the datetime string isn´t valid. The datetime string must match ISO 8601 format.
The error ocurrs when the following control is executed:
You've posted your question in the desktop forum, not cloud flows. 😉
You need to format the content of variables('Fecha') according to ISO 8601, before using addDays.