Internal pull-up resistors are enabled via software, but standard schematics include a 0.01µF to 0.1µF capacitor from each line (Dit and Dash) to ground to filter out RF interference (RFI) straying from your transmitter. 2. Transmitter Keying Output Circuit
Do not rush into soldering. Wire the basic paddles, sidetone, and output on a breadboard to test functionality using the K3NG GitHub code. k3ng keyer schematic