Setup my Echo Show 5 and Echo Connect also from Prime Day sale. Echo Connect is connected to my PBX. I use VOIP lines from Anveo Direct and M1.
"Alexa, call <contact>" , can be any contact from Alexa app which imported my mobile's contact list.
"Alexa, hang up"
Echo Show 5 will also show a keypad which can be voice controlled if you need to press any of the digit/#/* touch pads.
If your line has caller ID, it will show the caller ID of the caller as well.
Of course, need some tricks to coax Echo Connect to work with Singapore +65 DID.
Echo Show 5 is also not as polished as the rest of Echo's family. For example, the timezone don't have Singapore and I needed to find a substitute GMT+8 from Shanghai.
No visual feedback from the recognized voice command unlike Google Nest Hub. Still testing out the Smart Home screen options.