Lambda Limit is 512 Mb Lambda Limits, and cannot be changed.
The following quotas apply to function configuration, deployments, and execution. They cannot be changed.
/tmp directory storage 512 MB
If you need to run task that needs more space, one option would be convert the lambda to a container and run it as a fargate task.
The limits for fargate are 200Gb Fargate Tasks storage information
By default, Amazon ECS tasks hosted on Fargate using platform version 1.4.0 or later receive a minimum of 20 GiB of ephemeral storage. The total amount of ephemeral storage can be increased, up to a maximum of 200 GiB, by specifying the ephemeralStorage parameter in your task definition.