Yes, you can always remove or edit the text of the share option on any of your Fastcards, even though we recommend you don't remove it because it gives the opportunity to your customers to easily share it thus, reaching more people.
To edit your Share button: (Really simple)
TIP: Maintain your text short with a maximum of 3 words.
To remove your Share button:
While editing your Fastcard, Go to Config. on the left side of the screen.
NOTE: To show your share button again go to the config section and select "Show share button"