how toget the betaX like the betaX in the amd_example

[empathy-c]

I would like to know how to calculate the betaX matrix in amd_example, which is 148 x 26, when using other data set. When conducting MR analysis, the general data only includes SNP and the beta values of the gene where SNP is located or the nearest gene, while the beta values of all genes (risk factors) are not included. For example, if there are 148 instrumental variables and 26 risk factors, my betaX is 148 x 1 instead of 148 x 26,how I can get the betaX like amd_example?