Cypress is not defined in plugin file

[AnandChandrappa]

Am trying to access environment variables in index.ts file under Plugin directory. but cypress would not load and it throws below error message:

ReferenceError: Cypress is not defined

at Object. (/Users/achandrappa/Desktop/Twilio/Code_Repo/Automation/flex-monorepo/packages/flex-ui-e2e/cypress/plugins/index.ts:8:20)
at Module._compile (node:internal/modules/cjs/loader:1095:14)
at Module.m._compile (/Users/achandrappa/Library/Caches/Cypress/8.7.0/Cypress.app/Contents/Resources/app/packages/server/node_modules/ts-node/src/index.ts:536:23)
at Module._extensions..js (node:internal/modules/cjs/loader:1147:10)
at Object.require.extensions. [as .ts] (/Users/achandrappa/Library/Caches/Cypress/8.7.0/Cypress.app/Contents/Resources/app/packages/server/node_modules/ts-node/src/index.ts:539:12)
at Module.load (node:internal/modules/cjs/loader:975:32)
at Function.Module._load (node:internal/modules/cjs/loader:822:12)
at Module.require (node:internal/modules/cjs/loader:999:19)
at require (node:internal/modules/cjs/helpers:102:18)
at runPlugins (/Users/achandrappa/Library/Caches/Cypress/8.7.0/Cypress.app/Contents/Resources/app/packages/server/lib/plugins/child/run_plugins.js:175:15)
at Object. (/Users/achandrappa/Library/Caches/Cypress/8.7.0/Cypress.app/Contents/Resources/app/packages/server/lib/plugins/child/index.js:8:25)
at Module._compile (node:internal/modules/cjs/loader:1095:14)
at Object.Module._extensions..js (node:internal/modules/cjs/loader:1147:10)
at Module.load (node:internal/modules/cjs/loader:975:32)
at Function.Module._load (node:internal/modules/cjs/loader:822:12)
at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:81:12)