Your lock file does not contain a compatible set of packages. Please run composer update.
Problem 1
- mpdf/mpdf is locked to version v7.0.0-beta2 and an update of this package was not requested.
- mpdf/mpdf v7.0.0-beta2 requires php ^5.6 || ~7.0.0 || ~7.1.0 -> your php version (7.4.8) does not satisfy that requirement.
Problem 2
- yiisoft/yii2-composer is locked to version 2.0.5 and an update of this package was not requested.
- yiisoft/yii2-composer 2.0.5 requires composer-plugin-api ^1.0 -> found composer-plugin-api[2.0.0] but it does not match the constraint.
Problem 3
- yiisoft/yii2-composer 2.0.5 requires composer-plugin-api ^1.0 -> found composer-plugin-api[2.0.0] but it does not match the constraint.
- yiisoft/yii2 2.0.12 requires yiisoft/yii2-composer ~2.0.4 -> satisfiable by yiisoft/yii2-composer[2.0.5].
- yiisoft/yii2 is locked to version 2.0.12 and an update of this package was not requested.
You are using Composer 2, which some of your plugins seem to be incompatible with. Make sure you update your plugins or report a plugin-issue to ask them to support Composer 2.
Your lock file does not contain a compatible set of packages. Please run composer update.
Problem 1
- mpdf/mpdf is locked to version v7.0.0-beta2 and an update of this package was not requested.
- mpdf/mpdf v7.0.0-beta2 requires php ^5.6 || ~7.0.0 || ~7.1.0 -> your php version (7.4.8) does not satisfy that requirement.
Problem 2
- yiisoft/yii2-composer is locked to version 2.0.5 and an update of this package was not requested.
- yiisoft/yii2-composer 2.0.5 requires composer-plugin-api ^1.0 -> found composer-plugin-api[2.0.0] but it does not match the constraint.
Problem 3
- yiisoft/yii2-composer 2.0.5 requires composer-plugin-api ^1.0 -> found composer-plugin-api[2.0.0] but it does not match the constraint.
- yiisoft/yii2 2.0.12 requires yiisoft/yii2-composer ~2.0.4 -> satisfiable by yiisoft/yii2-composer[2.0.5].
- yiisoft/yii2 is locked to version 2.0.12 and an update of this package was not requested.
You are using Composer 2, which some of your plugins seem to be incompatible with. Make sure you update your plugins or report a plugin-issue to ask them to support Composer 2.