getting thiserror TS2339: Property 'markPrice' does not exist on type 'MarkPrice | MarkPrice[]

[error TS2339: Property 'markPrice' does not exist on type 'MarkPrice | MarkPrice[]'. Property 'markPrice' does not exist on type 'MarkPrice[]'.

return this.floorPrecised(
  ((await this.usdmClient.getMarkPrice(
    { isIsolated: "FALSE", symbol: symbol }
  )).markPrice), pricePrecision 
);

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