Compile your own by yourself, with autobuild or download a precomiled one above:
RaspiOS_RPi-4_2021-01-11_5.4.83-v7l_mptcp_v0.95.img: https://drive.google.com/file/d/1-poyVvIGQa0nVfO3lfg2j0bPx6TBIHYD/view?usp=sharing
OUTDATED
RaspiOS_RPi-4_4.19.142-v7l+_mptcp_0.95.img: http://ul.to/f88rcsmm
RaspiOS_RPi-3_4.19.142-v7+_mptcp_0.95.img: http://ul.to/xzu9yg4q