error initializing umi with secret key

I am trying to initialize an UMI instance using my secret key, but it;'s failing with

/home/jimii/Documents/crew/seatrees-minting-api/src/services/mintService.ts:40        const keypair = this.umi.eddsa.createKeypairFromSecretKey(                           ^TypeError: Cannot read properties of undefined (reading 'eddsa')    at new MintService (/home/jimii/Documents/crew/seatrees-minting-api/src/services/mintService.ts:40:28)    at Object.<anonymous> (/home/jimii/Documents/crew/seatrees-minting-api/src/controllers/mint.ts:7:21)    at Module._compile (node:internal/modules/cjs/loader:1241:14)    at Module.m._compile (/home/jimii/.nvm/versions/node/v20.8.1/lib/node_modules/ts-node/src/index.ts:1618:23)    at Module._extensions..js (node:internal/modules/cjs/loader:1295:10)    at Object.require.extensions.<computed> [as .ts] (/home/jimii/.nvm/versions/node/v20.8.1/lib/node_modules/ts-node/src/index.ts:1621:12)    at Module.load (node:internal/modules/cjs/loader:1091:32)    at Function.Module._load (node:internal/modules/cjs/loader:938:12)    at Module.require (node:internal/modules/cjs/loader:1115:19)    at require (node:internal/modules/helpers:130:18)

Code

        const keypair = this.umi.eddsa.createKeypairFromSecretKey(            Uint8Array.from(PAYER_KEYPAIR)        );        this.umi = createUmi(SOLANA_RPC_ENDPOINT);        this.umi.use(mplBubblegum()).use(keypairIdentity(keypair));