Open an instrument - there is a keyboard at the bottom of it unless you turned it off. Ignore the arrow in the image below. See the keyboard? You can play it with the mouse, not your computer keyboard, and you cannot record by playing the keys of the keyboard shown in the image.
Use the keyboard that is in the window below. Again, ignore the other stuff - I used this image for another purpose. See the keyboard at the bottom of the screen? That one. And you can play it either with the mouse or the keys on your computer keyboard. Set the instrument to MIDI record and you can record by playing on this keyboard or your computer keyboard.
When you open the keyboard in Samplitude, you will see letters on the keyboard like in the image below. They correspond to the key of your computer keyboard.
Open an instrument - there is a keyboard at the bottom of it unless you turned it off. Ignore the arrow in the image below. See the keyboard? You can play it with the mouse, not your computer keyboard, and you cannot record by playing the keys of the keyboard shown in the image.
Use the keyboard that is in the window below. Again, ignore the other stuff - I used this image for another purpose. See the keyboard at the bottom of the screen? That one. And you can play it either with the mouse or the keys on your computer keyboard. Set the instrument to MIDI record and you can record by playing on this keyboard or your computer keyboard.
When you open the keyboard in Samplitude, you will see letters on the keyboard like in the image below. They correspond to the key of your computer keyboard.