You can enable touch ID (as well as Face ID in your supported device) to access your Qapital account.
Head to the 'Profile' tab (which looks like a profile silhouette) and press the 'Gear' in the upper right hand corner. Select the 'Passcode & Touch/Face ID' banner, then unlock Touch/Face ID.
Please note, you may need to enable a Passcode first in order to unlock this feature.