I have R 3.6.1 and when I try to install the package ph525x using the command "BiocManager::install('ph525x')", it gives me the following error:

"package ‘ph525x’ is not available (for R version 3.6.1) "

Does anyone know how I can install it?

This does not look like a package on CRAN or Bioconductor. install( ) will only search the repositories on CRAN and Bioconductor by default. The closest I found was this github package. If this is the correct package, you can install this package by including the github organization/username in the install command install("genomicsclass/ph525x")