The addon panel is available in 3D view > Sidebar > Item:

[ SET ]: This button turns ON only the Rigify layers that will be used.

REFERENCE:

First of all, for the addon to work, you need to position the character for calibration. This is essential because each character has specific measurements. Create an Action to save this reference pose, so you can recover it later (use Fake User button to protect it). In object mode, clear location and rotation, and insert LocationRotationScale keyframes. Change to pose mode, select the root, clear location and rotation, and insert LocationRotationScale keyframes too. Activate the Rigify layers using the [ SET ] button, then position the character like the model below, select all the bones and insert LocationRotationScale keyframes in all:

It is very important that when you change the current frame the character remains still. Then, if everything is right, capture the reference pose.

[ GET reference ]: This button captures the reference pose to memory.

MOVE:

First, create a new Action to separate from the reference pose. In the current version of the addon there are two types of walk available: walk_01 and walk_02. After selecting the type, choose which leg will be moved: Left or Right.

[ L ]: This button moves the left leg forward.

[ R ]: This button moves the right leg forward.

After clicking the [ L ] or [ R ] button, the addon adds an Empty to the scene. If you wish, rotate it to direct the movement. The displacement will happen on the y-axis of the Empty.

Also note, after clicking the [ L ] or [ R ] button, the panel change, there are new buttons:

[ ABORT ]: This button aborts the current movement.

[ Complete_? ]: This button generates the movement, step-by-step, while inserting the keyframes.

When you click on the [ Complete_? ] button for the first time, it places the character in the final position of the movement (look at the keyframes):

In every step you can move the bones to adjust the pose (don't forget to replace the keyframes). When you click on the [ Complete_? ] button for the second time, it places the character in the middle of the movement (look at the keyframes):

Straighten the bones if you wish. When you click on the [ Complete_? ] button for the third time, the movement will be finished (look at the keyframes):

At the end of the process, the panel returns to showing the [ L ] and [ R ] buttons.

CENTRALIZE:

After walking through the scene, it is possible to re-center the root. But first, it is important to go to the last frame of the walk, select the root and insert LocationRotationScale keyframes. Change to object mode and insert LocationRotationScale keyframes. Then advance one frame.

[ Centralize ]: This button starts the centering process.

After clicking the [ Centralize ] button, the addon adds an Empty to the scene. The program uses this Empty to re-center, so position and rotate it as you wish. You will notice that the panel has changed too. There are two alternatives: center the root and keep the object in the same place; or center the object and the root.

[ ABORT ]: This button aborts the centering process.

[ Root ]: This button only centers the root.

[ All ]: This button centers the object and the root.

The addon adds the keyframes and the panel returns to showing the [ Centralize ] button.

how to install:

Copy the .py file into the Blender installation folder, for example, blender > 3.1 > scripts > addons, or start the Blender, open the Preferences > Add-ons and click on the Install button to select the .py file. Now the addon will be listed and you can enable it by pressing the checkbox:

limitations:

The addon only works with modern versions of Rigify rigs (0.6.5 or later). It is necessary to maintain the original names of the bones and layers (or change the variables and commands in the script):