You can add a **VIA** ,  router the track at TOP layer, then press hot key B , will switch to bottom layer.
T  hotkey will help you switch from bottom to top

@dillon Thank you, but you will know if there is any other method to do this.

@dillon If I choose the method you mention, what size do you think you can leave the hole or pad, so it is discreet and functional.
regards

The default size is OK for us to fab the PCB. if you need, you can set them via attribute.

@dillon thank

Yo Buddy ... i recently had the same problem .. add your SMD component to schematic then to your PCB layout ... while in the PCB  layout highlight the SMD component ... On the "Components Attribute" tab (Top Right Side by Default) change the layer attribute from TopLayer to BottomLayer ... your SMD should have blue solder pads ... good ruck 👍

"...add your SMD component to schematic then to your PCB layout..."

Not quite.

Add your component to the schematic.

Then do all the Schematic Checks in (4) in (2) in:

https://easyeda.com/forum/topic/How-to-ask-for-help-and-get-an-answer-71b17a40d15442349eaecbfae083e46a

Then do Create PCB... or Update PCB... from the Schematic Editor (or Import Changes... in the PCB Editor).

:)