C8618QT, 4K Touch, which whiteboard software?

Good morning everyone,

We are using the above mentioned 86" C8618QT, in our conference room.

Currently, we are using software such as Windows-Ink or PowerPoint in order to draw something and write down notes by using the pen or simply the finger. However, we are not really happy with the usability. Sometimes it is just not working smoothly. Can someone recommend a whiteboard software which is more convenient to use?

Our requirements are:
Write and draw with pen or finger
Save the notes as jpeg or PDF
Easily create, add or delete the documents created

I am not an English native speaker so I hope you understand what I am trying to say! :)
Thank you in advance!