Load balance between ether and wlan

Please, I want to merge two connections between ether1 and WLAN1 and combine their speed into one. How can I do this on the Mikrotik router model RM950Ui-2HnD , Export into wlan2

You cannot combine two WAN inputs so that one session splits up their packets between the two to get the aggregate speed.
What you can do is load balance between them so making the entire throughput available for users.
Any one session, cannot use throughput greater than the max of one of the WAN connections.

Device with model name “RM950Ui-2HnD” doesn’t exist. If, however, this is about RB951Ui-2HnD … then it’s an old and relatively slow device, ether ports are 100Mbps only, wireless is N so realistically around 100Mbps as well. CPU is no rocket either, it could route at around 200Mbps in simple use cases … but if you’d configure router with a complex task such as WAN link load-sharing, real throughput would likely drop below 100Mbps (specially do with involvement of wireless interface, which all by itself is already a CPU hog).