Hello,
Actually I am doing a tutorial (https://hakyimlab.github.io/psychencode/generate_weights.html) where they indicate that I need a dbSNP150 reference table containing "chromosome, position, ref, alt, rsid, and dbSNPBuildID" information for the hg19 version of the human genome. I am stuck in this step, can anyone help me and indicate where can I find this information?
Since you are working in R, you can often use annotation that is provided as part of Bioconductor. The latest release of Bioconductor for example contains a copy of dbSNP [version 150][1] and [even newer ones][2]. 

However, the annotation provided by Bioconductor refers to another reference genome build (hg38 instead of the long outdated version hg19). Older (ancient!) versions of Bioconductor might still contain hg19 coordinates, but better use [LiftOver][3] to convert the latest annotation back to the older reference genome build. 

Alternatively, there is also [a hg19 annotation from dbSNP 135][4] in the current build. 


  [1]: https://bioconductor.org/packages/3.15/data/annotation/html/SNPlocs.Hsapiens.dbSNP150.GRCh38.html
  [2]: https://bioconductor.org/packages/3.15/data/annotation/html/SNPlocs.Hsapiens.dbSNP155.GRCh38.html
  [3]: https://bioconductor.org/packages/release/workflows/html/liftOver.html
  [4]: https://bioconductor.org/packages/3.15/data/annotation/html/FDb.UCSC.snp135common.hg19.html