Octopus intelligent flux - octopus control the charge and discharge for you
Octopus flux - you have to do it yourself
Easiest way is from the web portal, my inverter page, settings, timed charge - enable that and set the start and end times to match your off peak slot.
Also set a charge up to percentage, probably 100% or something near enough that this time of year. You may want to reduce that if you have solar as the spring and summer approaches.
Make sure eco mode is on too.
Don't mess with timed export or timed discharge settings (don't enable either of them) without first reading the various forum posts here about the problems with timed discharge / timed export
If you want to force an export during the super peak evening period, then you will probably need some form of automation to do that, e.g. home assistant. Search the forum for that to learn more.
A quick and dirty approach should you want to hold onto the battery charge til 4pm would be to set the timed charge to start circa 1am (I forget when off peak is) and end at 4pm.
Combine that with the percentage to charge to - e.g. maybe set that to 70% if you think it's going to be sunny. Adjust accordingly and it'll charge or discharge to that percentage, but should go beyond it if it charges from solar.
