If the glass door of the security door already has the word "福" on it, do I still need to put the word "福" on it?

Should be posted.

The word "福" should be posted outside the door to represent welcoming new blessings. Pasted on the back of the door, it loses the original meaning of pasting the word "福". Posting a blessing outside the door means good luck and good luck for the year.

It is a traditional custom to paste the character "福" on the pasting. During the Spring Festival, every household will paste large and small blessing characters on their doors, walls and lintels. Posting blessing characters during the Spring Festival is a long-standing folk custom.