How to create an app to integrate with third party API

Summary: I am trying to create an app to integrate third party API where I need to extract the code value but I couldn't extract it as it is not displaying in the URL

Expected: 

https://{vb-app-url}?code=eyJ0eXAiOiJNVCIsImFsZyI6IlJTMjU2Iiwia2lkIjoiNjgxODVmZjEtNGU1MS00Y2U5LWFmMWMtNjg5ODEyMjAzMzE3In0.AQoAAAABAAYABwCAOfSUX-fbSAgAgMV63F_n20gCAMXRE6lISM1KvW5wWrKt_hQVAAEAAAAYAAEAAAAFAAAADQAkAAAAMzkxMDdkZDQtM2ViNy00ZjJlLTk2ZjAtNWQzNzMyMTk1MzI2IgAkAAAAMzkxMDdkZDQtM2ViNy00ZjJlLTk2ZjAtNWQzNzMyMTk1MzI2NwDqpY_xSr_iTpEBtpH8vmgaMACAWYMiX-fbSA.EkhcYNGBQIyxXsibjvSWB74STUpuG6kWt8u3JxJLg6rerG9gI6OjL8ufFbSjHKKCerUHPFO5CN48adx_qYf4YGH12-idCVOBm89vAcLFe6Zy6me2KNSmPPEid3KNIOivNrA4KEn5y1T3ThzEFzcIIAFhFgwK4-UzrUy01Im-hhW5i3QpjdJtC4Jh0rMHmj8c_xxZj0iEPYkOtq7Rvpy2U5d8NXpYlpH2SFVdgWDote8Ety2jY9iM4bNuPb2EsHnfu_hmCo2S8xjqKBgsK2eNjlIZIcskKbrb7KTdZ6ho30bdwiEn86Xms9re-jcIXDfa5LkvOfNjQFRLYBx8T-t99Q