3 ISP with same network

I have client who require to make 3 ISP with same network to make bandwith load. Can someone asist to me? Thanks

each connection same bandwidth…
https://mum.mikrotik.com/presentations/US12/steve.pdf

Bandwidth based if not even…
https://mum.mikrotik.com/presentations/US12/tomas.pdf

When you have a full config, come back and post for review
/export (minus serial number and any public IP info)