Yeah, they frustratingly leave out the design of their circuit and the part from the paper but reference their older work.
ReSkin: versatile, replaceable, lasting tactile skins https://arxiv.org/abs/2111.00071
> Z- coordinate system [36]. For an overall sensing area of 20mm x 20mm (Figure 3), we measure magnetic flux changes using 5 magnetometers. Four magnetometers (MLX90393; Melexis) are spaced 7mm apart around a central magnetometer. All 3D-printed molds, circuit board files, bill of materials, and libraries used have been publicly released and opensourced on the website
a breakboard is available here https://www.adafruit.com/product/4022