How to pass a variable into non-query execution for backup (SQL)

Good morning campers!, I have a doubt about how to pass a string variable into a sql activity. See bellow:

fecha_date=“20190101”

Sql into non-query activity=
"USE Database_Name;

BACKUP DATABASE Database_Name
To DISK = 'C:\\Temp\\xxxxxxx'"+fecha_date+"'.bak'"

Output= File> C:\Temp\xxxxxxfecha_date.bak
The expected output is> C:\Temp\xxxxxx20190101.bak

If someone could give me a hand, I’ll really appreciate it…

@amaidana

try this by removing the single quotes.

“C:\Temp\xxxxxxx”+fecha_date+".bak"