Hi @ShayGur
You need to write an expression to replace new line characters with <br> tag. Pls refer the below example:

Expressions are written in the expression box as fx formulas (highlighted in above screenshot).
Expression used in the above example:
replace(outputs('Compose_2'),decodeUriComponent('%0A'),'<br>')
Pls replace 'outputs('Compose_2')' with actual variable used in your flow.
If this helps & solves your problem, please remember to give a 👍 and accept my solution as it will help others in the future.
Thanks